An Arab tribal leader was killed and another civilian injured Wednesday in separate bomb attacks in central Iraq, the police said. Sheikh Ali Shekhan al-Makadmi, an Arab tribal leader, was killed when a sticky bomb attached to his car went off at a main road in the southern part of the city of Dujail, some 60 km north of Baghdad, a local police source told Xinhua on condition of anonymity. Meanwhile, in the eastern province of Diyala, gunmen planted a bomb at the residence of a police officer in a town west of the provincial capital city of Baquba, some 65 km northeast of Baghdad, wounding a member of the official\'s family, a source from the provincial operations command told Xinhua. The targeted officer escaped the attack unharmed, and the Iraqi security forces have launched an investigation into the incident, the source said. Also in the province, Iraqi security forces have carried out search operations across the province over the past 24 hours and arrested five terror suspects, including two wanted individuals, and defused a roadside bomb, the source added. Violence remains common in Iraqi cities despite the dramatic decrease since its peak in 2006 and 2007 when the country was engulfed in sectarian killings.