Car bomb explosion near Baghdad international airport wounds five

A car bomb exploded on the perimeter of Baghdad's heavily guarded international airport complex on Sunday, wounding five people, security sources said.

The blast occurred at a security checkpoint close to a parking lot, where passengers are searched before boarding airport taxis, three sources said. The checkpoint is several kilometres from the terminal building.

Twitter accounts that support Islamic State (IS), distributed messages, saying the group claimed responsibility for the attack, by what they described as 'the first' suicide bomber to receive the Americans' exiting from the airport.

However, security and police sources gave no indication that any American had been targeted.

An airport official said authorities tightened security while air traffic was normal.

Around two hours later, a roadside bomb exploded in a commercial area of Baghdad, about five km (three miles) from the airport. Three people were killed and seven wounded, said security sources and medics.

Islamic State militants who swept through the north of the country in June, and hold large parts of western Iraq, have claimed responsibility for suicide bombings and other attacks in Baghdad and further afield.

The presence of the Sunni insurgents has fueled sectarian tensions, deepening a security crisis and drawing U.S. air strikes, after Western hostages were beheaded.

The air campaign, which includes neighbouring Syria, has helped to prevent further Islamic State advances in recent weeks.

The United States' top military officer, told American troops on Saturday, that the momentum in the battle with Islamic State was 'starting to turn', but predicted a drawn-out campaign lasting several years.