Two of the four Blackwater-affiliated contractors involved in a civilian shooting incident in Kabul earlier this month have fled to the U.S. in order to avoid possible prosecution from Afghan authorities, according to their attorney.

The four men worked as military trainers for Paravant LLC, an affiliate of Blackwater Worldwide, whose parent company is now called Xe after a recent name change. Paravant was assisting Raytheon Co. on a Defense Department contract.

Armed contractors working for the Defense Department have been a touchy issue in Iraq as well as Afghanistan because of civilian deaths when fighting sometimes erupts. In Afghanistan, the recent incident risks further inflaming anger over civilian deaths caused by U.S. forces, and is a test of the Afghan government's posture toward foreign contractors, who are set to dramatically increase as the Pentagon ramps up the number of troops there in the coming months.

Afghanistan does not have a formal agreement with the U.S. governing legal accountability for contractors, and issues about jurisdiction remain hazy. U.S. defense firms are very wary of subjecting their employees to legal systems in Iraq and Afghanistan.

Daniel Callahan, of Callahan & Blaine in Santa Ana, Calif., said that two of the men, Steve McClain and Justin Cannon, "slipped out" of their compound on Saturday and made it to a hotel in Kabul, where a friend helped them. Soon after they flew to Dubai, and then on to the U.S.

Their two colleagues, Chris Drotleff and Armando Hamid, were to follow, but Mr. Callahan has not heard from them since late Sunday. Paravant terminated the four men for contract violations following the May 5 nighttime shooting incident that left one Afghan bystander dead and wounded two others in a car.

He said his clients were held against their will by the company, a claim which Xe has denied.

"They didn't want to take a chance but they felt they were going to get flipped over to the Afghans," said Mr. Callahan, who previously representing the families of four Blackwater security guards killed in Iraq in a lawsuit against the company. "These guys called me on a Friday night and needed help getting free," he said. Blackwater has been criticized in the past for spiriting away contractors who may have broken rules or run afoul of local authorities.

The U.S. military has almost wrapped up its investigation of the incident, according to Lt. Col. Chris Kubik, a spokesman in Afghanistan. He said Paravant cooperated with U.S. authorities. "They kept the guys here until their portion of the investigation was done," he said. Afghan authorities have not asked for jurisdiction so far.

A Blackwater spokeswoman declined to comment.

According to Mr. Callahan, who had been in contact with the four men via an intermittent Internet phone connection, the contractors said they were traveling in the second of two company vehicles when a car came up behind them, passed, and then smashed into the lead vehicle. The four men got out of their vehicle when the Afghan car swerved toward them as if to run them over, prompting them to open fire.

The men were armed with AK-47 assault rifles because a manager told them to carry them, even though they weren't supposed to have weapons at that time, according to Mr. Callahan. The weapons allegedly came from a captured stockpile, he said.

A person familiar with the situation said that several of the contractors, who are former military personnel, had been drinking that night, in violation of their contract. Mr. Callahan said an allegation alcohol played a role in the incident is untrue. "We believe Blackwater is trying to paint these men as out on a lark and drinking so that the company can maintain its ability to work in Afghanistan after losing its work in Iraq," he said.