BAGHDAD - Five US service members were killed on Monday in central Iraq, the US military said, in one of the worst single tolls for American troops in the country this year.

The US statement gave no more immediate details, but local media earlier reported a rocket attack on a US military base in Baghdad.

US forces officially ended combat operations in Iraq last August ahead of a scheduled US military withdrawal at the end of this year. US fatalities in Iraq since last year have become more sporadic.

US troops are now mainly involved in a support and training role.

Violence in Iraq has generally dropped since the height of sectarian conflict in 2006-2007, but gun and bomb attacks still occur daily, often targeting local Iraqi security forces.