TIKRIT, Iraq, Feb. 21 (Xinhua) -- The death toll of a suicide car bomb attack targeting Iraqi security forces in Samarra city of Salahudin province on Monday rose to 12, with 18 others wounded, provincial police source told Xinhua.
The attack occurred in the morning when a suicide bomber rammed his explosive-laden car into a military base belonging to a quick reaction police force in northern Samarra, some 110 km north of Baghdad, the source from Salahudin's provincial operations command said on condition of anonymity.
Earlier, police reports said the attack was carried out by a car bomb parked outside the military base, left 10 people killed and 15 injured.
The attack hit the police force tasked with protecting Shiite pilgrims who usually come to the Sunni-dominated city of Samarra to visit the al-Askari shrine.
The shrine, which contains the tombs of Ali al-Hadi and Hisson Hassan al-Askari, the 10th and 11th of the Shiite's 12 most revered Imams, was visited by Shiite pilgrims from all over the world.
Samarra has been relatively calm for more than three years after Sunni tribes and powerful anti-U.S. insurgent groups turned to cooperate with the U.S. troops and Iraqi security forces against al-Qaida network in Iraq, which exercised indiscriminate killings against both Shiite and Sunni Muslim communities.
However, insurgents frequently attacked Shiite pilgrims who perform communal rituals in the Iraqi cities, killing and wounding dozens of them in attempts to provoke sectarian strife in the violence-shattered country.
Violence and sporadic high-profile bomb attacks continue in the Iraqi cities despite the dramatic decrease of violence over the last three years.
Special Report: Situation in Iraq