Baghdad - US troops killed a former Iraqi army officer in northern Iraq while twin bombings left six people injured in volatile Diyala province where the search is on for three suspected female suicide bombers, security officials said Tuesday.

In the northern Salahaddin province, a US force stormed Monday night the house of an officer in the former Iraqi army in the village of al-Sheikh in the Shirkat area, a local security official told Deutsche Presse-Agentur dpa.

The troops killed the officer, ordered his family out and set the house ablaze, the official said.

The ex-officer was working as a lorry driver in the area, according to the official.

The US military has not released any information on the incident.

In nearby Tikrit, a policeman was killed by a bomb overnight, the security official said.

The incident occurred when the policeman, driving the car of the province's police chief, was on patrol in Arbin street at 2:00 a. m. (Monday, 2300 GMT).

In Diyala, north-east of Baghdad, separate twin bomb blasts left six people injured, three of them policemen, security sources told the Voices of Iraq (VOI) news agency.

No further details were available.

A local official in Diyala said a Monday blast that left at least nine people dead and 14 injured in a market in Baquba was not carried out by a female suicide bomber as was earlier reported.

Ibrahim Bajlan, the head of the municipal council, told VOI that the investigation showed that a bomb was detonated in the market, causing the blast.

"Confusion occurred at first after the charred body of a woman was found near the scene of the blast, causing the authorities to believe that she was the assailant," Bajlan said.

Police received information that three women are currently in Baquba to carry out suicide bombings targeting government buildings, the official said.

Their names are known to the police but they cannot be identified among the masses of people, Bajlan said.

"We cannot search all the women in Diyala to uncover the suicide bombers," he added. (dpa)