Militants killed nine people, including five soldiers, in Iraq on Thursday, officials said, the latest in a spike in violence that the government has so far failed to stem.

Militants killed nine people, including five soldiers, in Iraq on Thursday, officials said, the latest in a spike in violence that the government has so far failed to stem.

Security forces have in recent weeks carried out some of their biggest operations since the 2011 withdrawal of US forces.

In the deadliest single attack, a suicide bomber detonated a tanker truck rigged with explosives at an army checkpoint along a highway in the western province of Anbar, killing four people, according to security and medical sources.

The attack, which struck close to provincial capital Ramadi along the route connecting the city to the Syrian border, killed three soldiers and a civilian and wounded 14 others.

Also on Thursday, gunmen killed four people in the northern province of Nineveh, including two soldiers, and wounded another in two separate attacks, one of them targeting a checkpoint.

In the disputed city of Kirkuk, gunmen kidnapped and executed a lawyer, while a car bomb in a government car park wounded four people.

Violence has surged in Iraq this year to levels not seen since 2008 when attacks have killed at least 3,560 people since the beginning of 2013, according to figures compiled by Agence France Presse.