Iran soldier
An Iranian soldier stands guard in front of the shrine of the founder of the Islamic Republic of Iran Ayatollah Ruhollah Khomeini in Behesht Zahra cemetery, south of Tehran, Feb. 1, 2016. Reuters

UPDATE: 6:53 a.m. EDT – The tense situation after the attacks on Iran’s parliament and the shrine of Ayatollah Ruhollah Khomeini came to an end after all the attackers were killed, local media reports said.

UPDATE: 5:20 a.m. EDT – The Islamic State group, also known as ISIS, claimed responsibility for the attacks on Iran's parliament and the Mausoleum of Ayatollah Khomeini, the group’s Amaq new agency said.

Iranian state TV says one of the attackers detonated a suicide vest on the fourth floor of the parliament office building as the siege continued.

UPDATE: 4:31 a.m. - Iran's Intelligence Ministry said Wednesday that the attacks at the Parliament and Tehran's Khomeini mausoleum
were perpetrated by terrorists.

Another explosion was heard in the Parliament, while Tasnim news agency reported that seven were killed in a shootout in the Iranian parliament. However, authorities are yet to confirm the number of casualties.

UPDATE: 3:52 a.m. EDT – Iran’s state TV reported that the attacks on the parliament and at the shrine of Ayatollah Ruhollah Khomeini were linked. Four attackers, including a suicide bomber, reportedly killed a security guard and wounded four other people at the shrine.

In the attack on the parliament, armed men injured a security guard.

The identity and the motive of the attackers remain unclear.

Original Story:

Armed men carried out twin attacks at the Iranian parliament and the shrine of Ayatollah Khomeini in the capital, Tehran, Wednesday morning. Iranian media reported the firing and the blast were heard as gunmen holed up inside the parliament.

There have been several conflicting reports on the number of casualties, with most reports saying at least five people have been injured. A guard was killed in the parliament shooting, the semi-official Tasnim news agency reported.

Four attackers were involved in the parliament attack and eight people were wounded, Iran's state media reported.

"There were three attackers armed with two Kalashnikov rifles and one colt pistol," lawmaker Elyas Hazrati was previously quoted as saying. However, the number was increased to four after reports from Iran state media surfaced.

State TV also reported one of the attackers was killed by security guards and that a woman was arrested following the attack.

This is a developing story.