Three senior officers were killed and another was seriously wounded on Saturday when a suicide bomber blew himself up inside a military camp in the Tikrit city, north of Baghdad, a local police source told Xinhua.

Earlier, the source said that two officers were killed and a third was wounded in the attack.

"A suicide bomber wearing an explosive-belt sneaked into a military camp in central Tikrit and blew himself up at about 8:30 a.m. (0530 GMT) inside a room in the building of the army officers where the four officers were gathering," said the source from the police of the Salahudin province, where Tikrit, some 170 km north of Baghdad, is located.

"The blast killed a lieutenant colonel, a major and a captain, and seriously wounded colonel Dakhil Hassan, commander of the 1st Battalion of the Tikrit-based the 4th Division of the Iraqi army," said the source on condition of anonymity.

Col. Hassan was evacuated to a U.S. military medical facility set up at a former Iraqi air base of Tikrit, he added.

Insurgents frequently mount attacks on Iraq's fledgling army and police troops, accusing them of being collaborators with the U. S. occupation forces.

Source: Xinhua