The U.S. military says a suicide bomber blew himself up beside a U.S. patrol in southwest Baghdad Saturday, killing two American soldiers and wounding two others.

The military gave no other details of the incident, saying only that it was under investigation. Military officials also say a U.S. Marine was killed in action Friday in Iraq's restive Anbar province.

News of the deadly incidents came a day after U.S. military officials said they had foiled a massive escape attempt by detainees at a prison camp in southern Iraq. Military officials said they found two large tunnels under Camp Bucca, which houses nearly 6,000 detainees.

The officials say the tunnels were almost complete but no prisoners escaped.

Some information for this report provided by AP and Reuters.