US Army Isis suicide bombing
Isis suicide bombers have attacked a US coalition base in Iraq. JUNG YEON-JE/AFP/Getty Images

Four Islamic State militants launched a failed suicide bomb attack on a US military base in Iraq, which resulted in the death of all bombers as US forces opened fired as they approached the base.

The US-led coalition says several Islamic State suicide bombers have attacked one of its bases in northern Iraq, without causing any Iraqi or foreign casualties.

US Army Col. Ryan Dillon, the coalition spokesman, says all the attackers were killed. According to reports the militants "detonated themselves once they realised they could no longer advance on the military base".

Dillon says Sunday's attack occurred in the area of the northern town of Hawija, one of the last pockets of IS control after the extremists were driven from Mosul earlier this year.

US-backed Iraqi forces have retaken all the major urban areas the extremists once held in Iraq, but IS remains capable of carrying out attacks on civilian and military targets.

On Thursday, an IS attack on a checkpoint and restaurant in southern Iraq killed more than 80 people and wounded dozens more.

London's terror threat level is critical after Isis claimed responsibility for an improvised bomb that was detonated on 15 September at Parsons Green station on the capital's underground rail network. The terrorist attack was carried out during rush hour at 8.20am, injuring 30 people.