Iranian politician Ayatollah Madani and three others were assassinated by an agent of the MEK who detonated a grenade during Friday prayers in Tabriz.

Mir Asadollah Madani Dehkharghani (1914 - 11 September 1981) was an Iranian politician and Shia cleric. He was the second Imam Jumu'ah of Tabriz, the Imam Jumu'ah of Hamadan, the representative of the Supreme Leader in East Azerbaijan for less than a year, and a member of the Muslim People's Republic Party. Madani was also Hamadan province's representative in the first term of the Assembly of Experts.

The People's Mojahedin Organization of Iran (PMOI), also known as Mojahedin-e-Khalq (MEK) or Mojahedin-e-Khalq Organization (MKO), is an Iranian dissident organization. It was an armed group until 2003, afterwards transitioning into a political group. Its headquarters is currently in Albania. The group's ideology was influenced by Islam and revolutionary Marxism; and while it denied Marxist influences, its revolutionary reinterpretation of Shia Islam was shaped by the writings of Ali Shariati. After the Iranian Revolution, the MEK opposed the new theocratic Government of the Islamic Republic of Iran, seeking to replace it with its own government. At one point the MEK was Iran's "largest and most active armed dissident group", and it is still sometimes presented by Western political backers as a major Iranian opposition group. The MEK is known to be deeply unpopular today within Iran, largely due to its siding with Iraq in the Iran–Iraq War and continued ties with the government of Saddam Hussein afterwards.

Friday prayer, or congregational prayer, is the meeting together of Muslims for communal prayer and a service at midday every Friday. In Islam, the day itself is called Yawm al-Jum'ah, which translated from Arabic means "Day of Meeting", "Day of Assembly" or "Day of Congregation".

Tabriz is a city in the Central District of Tabriz County, in the East Azerbaijan province of northwestern Iran. It serves as capital of the province, the county, and the district. It is the sixth-most-populous city in Iran.