BAGHDAD: Car bombs killed 20 people, including five soldiers, in the Iraqi capital and the city of Ramadi to the west on Saturday, police and medical sources said, in attacks that resembled operations carried out by Islamic State (IS) militants.

Hours after the violence Al-Hadath television station reported that US-led air strikes targeted a gathering of Islamic State leaders in Iraq's western province of Anbar, possibly including the group's leader Abu Bakr al-Baghdadi.

Iraqi security officials were not immediately available for comment on the report from the station, part of Saudi-owned al-Arabiya television, and there was no immediate word from the US military.

Two bombs exploded in separate attacks in Baghdad's mainly Shia Amil district, said a police source.

“A driver parked his car and went to a cigarette stall then he disappeared. Then his car blew up, killing passersby,” said the police source, describing one of the two attacks in Amil.

In the mostly Shia al-Amin area of Baghdad, another car bomb killed eight people, medical sources said.

The attack by a suicide bomber on a checkpoint in Ramadi in western Anbar province killed five soldiers.

“Before the explosion, the checkpoint was targeted with several mortar rounds. Then the suicide humvee bomber attacked it,” said a police official.

“Some troops came to the scene. They were attacked by mortars. A confrontation took place for one hour.”

There was no immediate claim of responsibility for the bombings.

Western and Iraqi officials say US-led air strikes are not enough to defeat the Al Qaeda offshoot that holds parts of Iraq and Syria and is fighting to expand what it calls a caliphate.

Iraq must improve the performance of its army and security forces in order to eliminate the threat from the group, which wants to redraw the map of the Middle East, the officials say.

President Barack Obama has approved sending up to 1,500 more troops to Iraq, roughly doubling the number of US forces on the ground, to advise and retrain Iraqis in their battle against Islamic State.

The United States spent $25 billion on the Iraqi military during the US occupation that toppled Saddam Hussein in 2003, and triggered an insurgency that included Al Qaeda.

Washington wants Iraq's Shia-led government to revive an alliance with Sunni tribesmen in Anbar province which helped US Marines defeat al Qaeda. Such an alliance would face a more formidable enemy in Islamic State, which has more firepower and funding.

Police Colonel Shaaban Barazan al-Ubaidi, commander of a rapid reaction force in Anbar, said security forces retook eight villages. His account could not be immediately confirmed.