A US serviceman who allegedly shot dead two female colleagues in Bahrain had attacked one of them in an earlier incident, according to sources.

It also emerged yesterday that US Navy security teams at first thought a gunman was still on the loose, after the shootings at the Naval Support Activity base, Juffair, on Monday.

Hundreds of personnel were evacuated from barracks within the base, as armed teams searched the building.

American Clarence Jackson, aged 20, was still clinging to life in the BDF Hospital last night, after apparently shooting himself in the head immediately after the killings.

The victims, both American, one aged 19 and of Spanish origin and the other aged 20, were room-mates in the barracks and were shot dead after Jackson rapped on their door, at around 5am, said sources.

They said Jackson had been under restrictions for allegedly attacking one of the women, thought to be his ex-girlfriend, weeks earlier.

It is understood that the restrictions had only just been lifted.

Sources also said investigators initially thought that a gunman was still on the loose, when the alarm was raised.

The base was immediately locked down and hundreds of personnel were reportedly evacuated from the barracks block where the killings took place.

Many were in underwear or nightclothes and had to be provided with clothing from the base stores, since they were not allowed back into their rooms for several hours, said sources.

Stars and Stripes, an official US military publication, reported yesterday that the incident took place on the fourth floor of the barracks, which houses both visiting military personnel and junior enlisted sailors.

The barracks are reportedly less than 50 metres from the Freedom Souq, a popular shopping and recreation area within the base.

The complex, which opened last year, includes a Navy Exchange, movie theatre, food court, fitness centre and a barber shop.

Personnel living in the barracks were initially evacuated to the nearby gymnasium, said the report.

The lock-down at the base was lifted after about an hour, but it was apparently several hours before personnel were allowed back into the barracks. "At around 2pm, the base made an announcement over the Freedom Souq's public address system that local personnel on the first floor of the barracks could return to their rooms, but use only the main entrance," it said. Military chaplains offered support for those emotionally shaken by the shootings, said the publication. US Navy spokeswoman Lieutenant Denise Garcia wound not comment last night on any of the reports but said Jackson was still in the hospital and under treatment, though she did not confirm his identity. "His condition remains unchanged and investigations are still going on," she said. The dead women's bodies were initially taken to Salmaniya Medical Complex, but later removed. Navy officials have still not officially released the identity, nationality and ages of all those involved. A Navy spokeswoman had said on Monday that the victims, as well as the alleged killer, were part of the base security team and that Jackson was authorised to have a gun as part of his duties. She was unable to confirm whether the weapon had been recovered from the scene. Officials would still not reveal the type of gun used, nor would they speculate on the relationship between the three. Medical sources said Jackson was in a coma and was unlikely to survive. mandeep@gdn.com.bh