Four US soldiers were killed in separate attacks in Baghdad and north of the Iraqi capital, the military said Wednesday. Two soldiers died Tuesday in an explosion in Diyala province, the US military said in a statement. Four other soldiers were wounded in the blast and evacuated to a US combat hospital, it said. Diyala is a dangerous area known to have a strong al-Qaida in Iraq presence, northeast of Baghdad. Another soldier was killed and five others wounded by an explosively formed penetrator, or EFP, Wednesday in central Baghdad, the military said in another statement. An Iraqi civilian was killed and two others were also wounded in the blast, it said.