Unit 121
Unit 121 is the secret assassination squad of Lebanese militant organization Hezbollah. The squad reports directly to the Hezbollah's Secretary-General. The unit is believed to have carried out deadly car bomb attacks against Lebanese army and political leaders and journalists, including former Prime Minister Rafic Hariri, officer Wissam Eid, military officials Wissam al-Hassan and François al-Hajj, diplomat Mohamad Chatah, and political activist Lokman Slim.Description
Unit 121 Hezbollah's assassination squad operates directly under the organization's Secretary-General. The unit existence received public attention only during the Special Tribunal for Lebanon, when three of its men, Salim Ayyash, Hassan Habib Merhi, and Hussein Hassan Oneissi were indicted. The extremely secretive unit includes only a few dozen members, operating in isolation form the rest of the organization. Each operation is pre approved with Hezbollah's leadership, showing is strictness and organization. Hezbollah's modus operandi includes targeted killings to eliminate rivals and potential threats, by using highly skilled bombmakers and a sophisticated chain of command to help protect its high ranked operatives form detection and accountability.
Unit 121 was formed by Imad Mughniyeh. After Mughniyeh's death in 2008, leadership of the unit passed to Mustafa Badr al-Din, until his death. In 2016, the unit came under Hezbollah Secretary-General Hassan Nasrallah, with Talal Hamiyeh assuming leadership of the unit.Operations
Unit 121 has carried out deadly car bomb attacks eliminating Lebanese military and political leaders as well as journalists. By 2020 the unit had carried out at least four other assassinations using car bombs, in addition to killing Rafic Hariri. The victims of these bombing s were Wissam Eid, Lebanese investigator to the Hariri case, Wissam al-Hassan, Lebanese army brigadier general and Hariri's security chief, François al-Hajj, a Lebanese major general, and Mohamad Chatah, an economist and diplomat.
The unit was first revealed during the 2020 Special Tribunal for Lebanon, held by the United Nation, that concluded the Unit 121 was responsible for the 2005 assassination of Rafic Hariri killing the former Lebanese prime Minister and 21 others. On 18 August 2020, the STL convicted Salim Jamil Ayyash, the unit's commander, in absentia for leading the team that carried out the attack.
On 4 February 2021, according to reports, Unit 121 allegedly assassinated political activist and Hezbollah opponent Lokman Slim. During the time period leading to Slim's assassination, Hezbollah pursued a campaign of political incitement against Slim.
On 2, December, 2025, Israeli sources revealed information connecting the unit to assassination executed against four individuals who could provide information about Hezbollah's link to the 2020 Beirut explosion. According to the information, Unit 121 executed journalist Lukman Slim, photographer Joe Bejjani, Joseph Skaff, the former head of customs inspections at the Beirut Port, Mounir Abou Rjeily, who headed the anti-smuggling division in the customs department.Key members
Salim Ayyash
was a Lebanese senior Hezbollah militant operative, who was the leader of its assassination squad, Unit 121. He became well known after his indictment by the Special Tribunal for Lebanon as one of the major individuals involved in the assassination of Lebanese Prime Minister Rafic Hariri.Mustafa Badreddine
was a senior Hezbollah officer. In addition to being the cousin and brother in-law of Imad Mughniyeh, he served under him for many years as his most trusted associate. Later he took his role as the head of Hezbollah's Islamic Jihad Organization. It is said he was behind and took part in some of Hezbollah's most notorious operations that include the Beirut and Kuwait bombings and the assassination of Rafic Hariri. Badreddine was killed in 2016 in a bombing near Damascus International Airport. Who was behind the bombing remains unclear.Hassan Habib Merhi
Hassan Habib Merhi, born 12 December 1965 in Lebanon, was a leading member of Unit 121. It was proven that he was among the leading figures behind the assassination of Lebanese PM Rafic Hariri. Hassan was found guilty for his part in the assassination at the UN backed Special Tribunal for Lebanon.Hussein Hassan Oneissi
Hussein Hassan Oneissi, born February 11, 1974, was one of the key members heading Unit 121. Oneissi played a major role in the planning and assassination of Lebanese Prime Minister Rafic Hariri. On June 20, 2020 he was sentenced in absentia at the UN-backed Special Tribunal for Lebanon, for life imprisonment and international arrest warrants were issued against him.Notable assassinations
Rafic Hariri
, a former Lebanese Prime Minister, was assassinated on February 14, 2005, in Beirut through a massive truck bomb that killed him and 21 others. The attack sparked widespread protests and political upheaval, leading to Syria's withdrawal from Lebanon after being widely accused of involvement. In 2020, the Special Tribunal for Lebanon convicted Salim Jamil Ayyash, a major Hezbollah operative in absentia for orchestrating the assassination.Luqman Slim
Luqman Slim was a prominent Lebanese activist and outspoken critic of Hezbollah and linking the organization to the 2020 Beirut explosion. He was assassinated on February 4, 2021. His body was found in southern Lebanon with gunshot wounds, sparking widespread condemnation and allegations of political motives. The killing highlighted growing threats to dissenting voices in Lebanon but remains officially unsolved.His sister, Rasha al-Amir stated her brother got threats from Hezbollah.Marwan Hamadeh
, a Lebanese politician, member of the Progressive Socialist Party, who was closely allied with Druze leader Walid Jumblatt, and critic of Syrian influence. He survived an assassination attempt on October 1, 2004, when a car bomb targeted his convoy in Beirut. The attack killed his bodyguard and injured several others, intensifying tensions over Syria's role in Lebanon. The incident is often linked to the wave of political violence preceding Rafiq Hariri's assassination by Hezbollah.Samir Kassir
, was a Lebanese journalist known for his criticism of the Syrian influence in Lebanon. On 2, June 2005, he was assassinated in Beirut. According to reports a bomb that was planted in his car exploded. This assassination that shook the country, was seen as part of a larger violent political campaign. Kassir’s killing made people in Lebanon demand justice and answers during a time of political trouble.George Hawi
, was a former leader of the Lebanese Communist Party and known for his criticism against the Syrian influence in Lebanon. He was assassinated on 21, June, 2005, in Beirut when a bomb exploded under his car. This assassination fits the modus operandi used to target anti Syrian critics in Lebanon, as well as deepened the political division within the country. It further fueled the demands to end foreign influence in Lebanese affairs.Gebran Tueni
, was a well known Lebanese journalist and editor of An-Nahar newspaper. He was assassinated on December 12, 2005, in Beirut when a car bomb exploded under his vehicle. Tueni was known for his criticism against the Syrian influence in Lebanon, playing a major role in the Cedar Revolution, that aimed to put an end of the Syrian dominance in the country. The Assassination made tensions worse and was seen as one of several political assassinations by Hezbollah and its allies against opposition in Lebanon.Pierre Amine Gemayel
, was a Lebanese politician, member of the Kataeb Party, that was known as strong critic of the Syrian influence in Lebanon. On 21, November 2006 his convoy was ambushed by gunmen and he was assassinated close to Beirut. His assassination took place during a time of great turmoil in Lebanon, and was seen as an attack on Lebanese people who support Lebanon's independence. Gemayel’s death caused further tension between political groups, raising fear of another civil war.Antoine Ghanem
, was a Lebanese politician and member of the Kataeb Party, known as a figure opposing the Syrian influence. On 19 September 2007 he was assassinated in Beirut. A car bomb exploded near his car. His assassination was regarded as part of the ongoing violent political campaign targeting those who appose Syria's influence in Lebanon.Elias Murr
, was Lebanon's Defense Minister during the early 2000s. on 12, July 2005 he survived as assassination attempt as a car bomb exploded next to his convoy in Antelias. The explosion critically wounded Murr, killed one person and injured several others. The attempt on his life, a known figure for his efforts to stabilize Lebanon, was viewed as part of the violent political campaign targeting those who apposed Syria's intervention in Lebanon.Walid Eido
, was a Lebanese political figure and member of the Future Movement, known for his support of an independent Lebanon and opposition to Syria's influence in Lebanon. He was assassinated on 30, June 2007, in Beirut, where a bomb exploded next to his convoy. His assassination that took place during a time of political tension in Lebanon, was viewed as part of a violent political campaign to eliminate those opposing Syria's influence in Lebanon.Mohamad Chatah
, was a former Lebanese finance minister, know as a critic of the influence of Hezbollah and Syria in Lebanon. On 27, December, 2013 he was assassinated in Beirut, as a car bomb exploded next to his convoy. His assassination was that came at time of political tension in Lebanon, was viewed as an attempt to eliminate opposition to Hezbollah's and Syria's influence.Francois Elias Hajj
Francois Elias Hajj, was a senior Lebanese Army officer, known for his role and attempts to stabilize Lebanon during a time of political tension. On 12, December, 2007, he was assassinated in the Beirut suburb of Baabda as a car bomb exploded next to his car. His assassination was regarded as an attempt to destabilize the Lebanese military and Lebanon's political system.