TEHRAN, Iran (CNN) -- Attackers have mounted simultaneous gun and suicide bomb assaults on Iran's parliament building and the tomb of the republic's revolutionary founder in Tehran.
At least seven people were killed and 35 others injured in the twin assaults, the semi-official Fars agency reported. The attacks were the most audacious
State media reported that gunmen stormed the parliament building in Tehran and went on a shooting spree. At least one attacker detonated a suicide bomb. Five people died and at least 25 were injured there, Fars reported.
At the same time, a gun and suicide bomb attack targeted the Ayatollah Khomeini mausoleum on the southern outskirts of the Iranian capital. Two people died and 10 were injured at the shrine, Fars said.
A woman was arrested after the attack at the tomb, Fars reported, adding that another attacker has been surrounded by security officers.
CNN has not independently verified the number of victims and it was not immediately clear whether the number of dead included the suicide bombers.
The attackers were holding a number of hostages inside the highly-fortified parliament building, Press TV reported, as Iranian officials scrambled to establish who was behind the attacks or whether they were coordinated.
A picture from semi-official Fars news agency shows a man lowering a young boy from a window of the parliament building onto the street as another man holding a gun watches over them from another window. The man with the gun is reportedly a policeman helping with the evacuation.
Attacks of this nature are extremely rare in Iran, particularly in the highly-controlled capital where tourist and government sites are tightly policed.
Gun ownership is heavily controlled in Iran, raising speculation that the attackers' guns were smuggled into the country.
Iran's parliament, also called the Islamic Consultative Assembly or Majlis, has 290 members. It has female members and has representatives for religious minorities including Christians, Zoroastrians and Jews.
It is currently unclear how the attacker or attackers entered the parliament building, which has multiple security checkpoints.
The location of the mausoleum attack is symbolic, targeting the tomb of the Islamic Republic's founder and first supreme leader Ayatollah Ruhollah Khomeini. He led the revolution that overthrew the Shah in 1979 and was Iran's leader for 10 years.
The mausoleum is located around 25 kilometers (15 miles) from the parliament.
Such attacks in Iran are rare, but the country -- with its largely Shiite population -- has been involved in military actions against Sunni terrorist groups such as ISIS, who regard Shiites as apostates.
Last year, Iran's government said it thwarted "one of the biggest plots" by terror groups targeting Tehran and other major cities during the month of Ramadan. This year's holy month started almost two weeks ago on May 26.
The last major attack in Iran was in 2010 when a Sunni extremist group carried out a suicide attack against a mosque in Sistan-Baluchistan killing 39 people. Kurdish groups have carried out small scale attacks against Iranian security forces in the north-west of the country.