TEHRAN: Twelve people were killed in twin attacks on Iran´s parliament complex and the shrine of its revolutionary leader claimed by the Daesh militant group on Wednesday, its emergency services chief said.

A total of 39 people were wounded in the two attacks, and rescue operations are continuing, Pir Hossein Kolivand said.

Attackers raided Iran's parliament and set off a suicide bomb at the Mausoleum of Ayatollah Khomeini in Tehran. The Iranian Intelligence Ministry said security forces had arrested a "terrorist team" planning a third attack, without giving further details.

The attacks, targeting parliament and the shrine of the Republic's revered founder, Ayatollah Khomeini, took place less than a month after the re-election of President Hassan Rouhani, a moderate.

Three assailants, one with a pistol and two with AK-47 assault rifles, attacked the parliament building in central Tehran, lawmaker Elias Hazrati told state television.

Iran's state broadcaster IRIB reported that one attacker detonated a suicide vest there, though some other news agencies said the explosion might have been caused by grenades thrown by the assailants.

Armed men launched two attacks in Iran's capital on Wednesday morning, killing a guard at the parliament and wounding several people in the Mausoleum of Ayatollah Khomeini. Photo: Iranian news agency Mizan

Tasmin news agency said there were unconfirmed reports the attackers had taken four hostages inside the parliament building. Up to seven people died and several others were wounded, it added.

About half an hour later, attackers opened fire at the mausoleum a few kilometers south of the city, wounding several members of the public, Iran's English-language Press TV said.

One attacker detonated a suicide vest, one was killed by security forces and other assailants were arrested, the Governor of Tehran was quoted as saying by IRIB.

"The atmosphere is tense. It is a blow to Rouhani. How can four armed men enter the parliament, where a very tight security has always been in place," said a senior official, who asked not to be named. 

Rouhani retained power with a landslide victory over candidates supported by the hardline clergy and the Revolutionary Guards Corps (IRGC), the country's most powerful security force in charge of ensuring national security.

Iranian TV said parliament had resumed, and broadcast footage of what it said was the opening session proceeding normally.

Daesh claims responsibility for attacks

Daesh claimed responsibility for attacks on Iran's parliament and Ayatollah Khomeini's shrine on Wednesday, the group's state news agency AMAQ said.

"Fighters from [Daesh] attacked Khomeini's shrine and the Iranian parliament in Tehran," the news agency said.

Another terrorist plot foiled

The head of the anti-terrorism department in the Iranian Intelligence Ministry said they foiled a third terrorist plot and have arrested "a terrorist team", state broadcaster IRIB reported.

Iran's intelligence ministry has also asked people to avoid public transport, according to IRIB.