A policeman was killed and 26 others were wounded, including four Iranian Shiite pilgrims, in separate attacks in central Iraq on Wednesday, the police said. A policeman was killed in Iraqi\'s western province of Anbar when a sticky bomb attached to a car and a roadside bomb coordinately ripped through the industrial area in northern the provincial capital city of Ramadi, some 100 km west of Baghdad, a source from operations command of Anbar told Xinhua on condition of anonymity. The blasts also wounded eight policemen and 12 civilians at the site, the source said. The attackers apparently followed old tactic of creating an initial explosion to attract security forces and people before setting off another blast to get heavier casualties, the source added. Near Baghdad, a roadside bomb detonated near a bus carrying Iranian Shiite pilgrims in Taji area, some 20 km north of Baghdad, wounded four pilgrims abroad, an Interior Ministry source anonymously told Xinhua. Insurgents frequently attacked Iranian pilgrims who flock in large numbers to Iraq to visit holy Shiite shrines since the U.S.- led invasion in 2003 that toppled Saddam Hussein\'s Sunni regime and set up Shiite-led government. In a separate incident, a gunman threw a hand grenade on an Iraqi army vehicle on a highway in Baghdad\'s western district of Adel, wounding two soldiers, the source said. Sporadic attacks are still common in Iraqi cities despite the dramatic decrease of violence over the past few years.