Masked gunmen attacked Russian technicians heading to work at a major electric power station Wednesday, killing two of them and prompting the company employing them to order its staff out of Iraq, officials said Wednesday.

The attack was the latest targeting efforts to rebuild infrastructure in Iraq, a vital part of the U.S. campaign to win support among Iraqis.

Two Russian experts from the same firm, Interenergoservis (search), were kidnapped and a third Russian was killed in an attack earlier this month south of Baghdad. The two captives were later released.

In Moscow, the firm's executive director, Alexander Rybinsky, announced the full evacuation of company personnel from Iraq. Some 241 employees are expected to start leaving Thursday, Russia's ITAR-Tass and Interfax news agencies reported.

Police said the Russians were traveling by bus to the Dora power station (search) when they were ambushed a few hundred yards from the compound in southwestern Baghdad. One Iraqi was also killed, police said.

Dr. Adham Saadoun of the Yarmouk Hospital (search), where the wounded were taken, said some were seriously injured.

Seventeen Russian specialists were on the bus when it was attacked, Russian news agencies reported.

Just a day before the ambush, Interenergoservis chief executive Alexander Abramov announced plans to expand activities in Iraq. The company was reviewing a flood of offers, he told ITAR-Tass, including some from the Iraqi Ministry of Energy.

On May 10, a group of Russians working for the company were seized after their vehicle was attacked in Musayyib, about 40 miles south of Baghdad. A third worker was killed in the attack.

The men were released about 10 days later after mediation by Iraqi religious and political figures.

In April, three Russian and five Ukrainian employees were abducted and released unharmed the next day. Hundreds of workers for Russian companies were evacuated from Iraq shortly thereafter, but most decided to stay on.

In Moscow, the Russian Foreign Ministry said it had repeatedly warned Russian nationals of the dangers of living in Iraq, where violence is on the rise ahead of the return of sovereignty June 30.

The ministry blamed the deteriorating situation on the failure of the U.S.-run occupation authority "to guarantee the necessary security."

Russian experts have played a key role in attempts to improve electric power supplies as the summer's peak-use period approaches.

Attacks on infrastructure targets have stepped up in recent weeks. Bombings along key oil pipelines in northern and southern Iraq have resulted in temporary cutbacks in oil exports — the key to reviving Iraq's economy.

Coalition authorities have still been unable to guarantee uninterrupted, 24-hour-a-day electric power to Baghdad's 5 million people, adding to the public's frustration with the American-run occupation.