ISLAMABAD– A U.S. consular worker has been remanded in police custody for six days after shooting dead two armed assailants in Pakistan.

Raymond Davis may face murder charges after the pair approached him on a motorcycle shortly after withdrawing money from an A.T.M. in the eastern city of Lahore on Thursday.

Police say Davis believed the men intended to rob him in his car in a crowded street. He apparently produced a Bareta and opened fire.

One gunman was killed at the scene by four separate shots. The second died later in hospital from three rounds.

A third Pakistani was killed by a U.S. consulate S.U.V. as it rushed to Davis’s aid after he apparently called the mission for help. The consulate says it will surrender the vehicle and the driver to police for the official investigation.

Appearing Friday in a Lahore military court, Davis apologized to the two men’s families.

In a two-sentence statement Friday, the U.S. embassy confirmed that a consulate staffer "was involved in an incident yesterday that regrettably resulted in the loss of life."

The U.S. was working with Pakistanis to "determine the facts and work toward a resolution," it said.

But a Pakistani police officer described Davis, said to be from Virginia, as a “security official” at the Lahore consulate while others said he called himself a “technical adviser” to the authorities.

As foreign mission worker he enjoys diplomatic immunity but Davis’s case is complicated by a ban on foreigners from carrying weapons in Pakistan and by local self-defense laws.

Under Pakistani law one can only act in self-defense if attacked first. Merely being approached by someone wielding a gun is insufficient cause under law for the victim to pull the trigger. Also, when firing in self-defense it is only admissible to aim at non-life threatening parts of the assailant's body, such as arms or legs.

The killings complicate further an already fraught relationship the United States has with Pakistan, its most important ally in fighting terrorism and Islamic militancy.

Pakistani deaths at American hands are an immensely emotive issue here, where relentless CIA drone strikes aimed at insurgents have claimed the lives of hundreds of civilians in the past two years.

In recent weeks there have been rallies countrywide involving thousands of protesters, angry at the attacks that they view as an invasion of national sovereignty and resentful of the US-led occupation of Afghanistan which is often sold by radicals as an American war on Islam.

The U.S. Sate Department has just embarked on renewed efforts to improve America’s image with the Pakistan public amid tensions with the country’s government and the de facto ruling military.

The local provincial law minister, Rana Sanaullah, said no US pressure would be allowed to influence Davis’s case, should it come to a criminal court.

“We will not accept any pressure in this case. The guilty will be punished and the innocent will get justice,” he told reporters.