The Islamic State (Isil) has claimed responsibility for a coordinated attack by gunmen and suicide bombers on Iran’s parliament and the the shrine of Ayatollah Khomeini, the spiritual leader of the Iranian Revolution.

Teams of attackers struck the two sites in Tehran early on Wednesday morning, killing at least 12 people and wounding dozens of others, according to Iranian state media. If confirmed that Isil was behind the attack, it would be their most ambitious operation yet against Iran.

One suicide bomber blew themselves up at the Khomeini shrine, which is highly symbolic for Iran’s theocratic leadership. A second bomber later detonated their explosives at the parliament during a stand off with security forces.

Isil’s Amaq news agency released a short statement soon after the attacks saying: “Fighters from the Islamic State attacked the shrine of Khomeini and the Iranian parliament building in the centre of Tehran.”

The jihadist group claimed credit with unusual speed and released a video of the attackers inside the parliament building.