Thirteen died and 42 were injured after gunmen and suicide bombers attacked the Iranian parliament and the mausoleum of Ayatollah Khomeini in Tehran on the morning of June 7, Iranian officials said. A third attack was foiled, the officials added, but gave no other details. 

One of the four-strong group that entered the parliament building dressed as women died after detonating a suicide vest, while the other three were killed in a shootout with security forces, but it was unclear if their deaths were included in the given casualty toll.

The Islamic State (IS) group’s media arm Amaq claimed the attack. The BBC reported that IS had posted a video with purported footage from inside the parliament building. Terrorists are heard speaking with North African Arabic accents.

If confirmed as the work of IS, it would be the Sunni terrorist group's first attack inside predominantly Shiite Iran. The Iranians and their proxies are battling Islamic State inside Iraq and Syria.

Iran has suffered terror attacks in the past, but rarely in the cities or the capital. The bombings of separatist groups and Sunni extremists are largely restricted to the border region near Pakistan.

Four gunmen burst into the heavily-guarded Iranian parliamentary complex around 10.30am local time, local media said. Two attackers are shortly after said to have attacked the shrine. One of that duo died after triggering a suicide vest, while the other was shot dead by security personnel.

One MP, Elias Hazrati, described to the semi-official Tasnim News Agency how the gunmen, carrying weapons including AK-47 assault rifles and a pistol, entered the Islamic Consultative Assembly, or “Majlis”, firing at people inside. They did not manage to enter the parliamentary chamber.

The attackers managed to gain access to the compound even though it has in recent years been provided with extra security measures, including heavily fortified crash barriers and walls. The complex is surrounded by the capital’s bazaar district.

Some local media described the suicide bomber at the shrine as either a woman or a man dressed as a woman.