America's top two officials in Iraq on Monday condemned a surge of car bombings, attacks and retribution killings by extremists in Baghdad. The U.S. military also announced that a Marine helicopter carrying 16 people made an emergency landing Sunday in a lake in the volatile Anbar province west of Baghdad, killing one and leaving three missing, the military said Monday. Twelve passengers survived, the Associated Press reported. The incident did not appear to be due to enemy action but was being investigated, the command said. «We condemn in the strongest language the recent car bombings, attacks and retribution killings by extremists against peaceful Iraqis in Baghdad,» U.S. Ambassador Zalmay Khalilzad and U.S. Gen. George W. Casey, Jr., the top American military commander in Iraq, said Monday in a joint statement. «The true enemies of all Iraqis are the murderers who carry out these senseless and cowardly attacks, regardless of sect, tribe or ethnicity. They are terrified of progress in this country and are determined to sow sectarian discord for their own selfish agenda,» they added.