A police officer was killed and a policeman wounded on Sunday in two gunfire and bomb attacks in central Iraq, the police said. Major Majid Walid, an Interior Ministry officer, was killed in a drive-by shooting by armed men using silenced weapons while driving on a highway in eastern the capital city of Baghdad, an Interior Ministry source told Xinhua on condition of anonymity. Iraqi security forces have sealed off the scene and launched an investigation into the incident, the source said. In a separate incident, a policeman was wounded when three coordinated roadside bombs went off near his car in the town of Ishaqi, some 100 km north of Baghdad, a local police source told Xinhua. Sporadic attacks, including suicide bombings, are still common in Iraqi cities since the U.S. troops pulled out of the country late last year.