Four policemen were killed Tuesday in a drive-by shooting in the northern city of Mosul, police said. A police officer in Mosul said gunmen opened fire on eight off-duty policemen who were traveling in two civilian cars to work, killing four and wounding the rest. The attack took place in al-Amil, he said. Meanwhile in Baghdad, three people were killed when a car bomb went off at an outdoor market in al-Jihad, a neighborhood in western Baghdad, a police officer and a hospital doctor said. Thirteen others were wounded, they said. Also in the capital, a police officer said nine people, including four policemen, have been wounded in two separate roadside bombs targeting police convoys, Associated Press reported.