Multiple gunmen have stormed into Iran's parliament and taken hostages, according to the state news agency.

Four attackers reportedly launched the assault on parliament, which has wounded at least eight people.

One of the attackers has blown himself up in the parliament building, according to state TV.

There was also an attack on the shrine of Ayatollah Ruhollah Khomeini - Iran's revolutionary leader in the 1979 ouster of the shah - which has killed a security guard and wounded four people.

Police helicopters were circling over the parliament building and that all mobile phone lines from inside were disconnected, Iranian state media said.

The ISNA news agency said all entrance and exit gates at parliament were closed and that lawmakers and reporters were ordered to remain in place inside the chamber, where a session had been in progress.

State TV later said four attackers are involved in the parliament attack, and that eight people were wounded. Lawmaker Elias Hazrati said the attackers were armed with Kalashnikov assault rifles.

A picture reportedly showing the explosion released by Jamaran News shows an empty courtyard.

It was not immediately clear who was behind the attacks or if they were coordinated or if the other gunmen have been apprehended.

The unusual attacks in Iran's capital, Tehran, prompted the Interior Ministry to call for an urgent security meeting, according to the state-run IRNA news agency.

As Iran's first Supreme Leader, Khomeini is a towering figure in the country and was its revolutionary leader in the 1979 ouster of the shah.

Sunni extremists, including the Islamic State group, despise Shiite-majority Iran and are at war with Tehran's proxies in Syria and Iraq. Iran has also come under attack in the past by Arab insurgents. No one immediately claimed Wednesday's attacks.