Iraqi officials say a roadside bomb explosion has killed four off-duty soldiers near a city northeast of the capital, Baghdad.
Army Brig. Gen. Hamid Mohammed said the Tuesday afternoon blast hit their car as they headed to their unit near Tuz Khormato, a city 130 miles north of Baghdad.
Mohammed said security forces sealed off the area and started a search operation to find the attackers.
Violence has ebbed in Iraq since the height of the sectarian fighting from 2005 to 2007, but extremists frequently attack security forces in an attempt to undermine the Shiite-led government in Baghdad.