BAGHDAD: Six suicide bombers burst into an Iraqi ministry building, took hostages and killed at least 18 people including themselves on Thursday before security forces regained control, a senior official said.

The brazen attack on the building belonging to the Ministry of Transportation in northeast Baghdad coincides with a month-long standoff between the Iraqi army and anti-government fighters in the western province of Anbar.

A senior security source said the six militants took a number of hostages and killed four of them inside the building, which was used to receive visiting delegations. It was not immediately known where the other eight victims died.

Anti-government fighters, including the Al-Qaeda-affiliated Islamic State of Iraq and the Levant (ISIL), are currently in control of the city of Fallujah, which is being surrounded by the Iraqi Army.

The UN refugee agency said the standoff in Fallujah has driven more than 140,000 people from their homes, describing it as the largest displacement in Iraq since the sectarian slaughter that climaxed in 2006-07.