U.S. Navy Officer Slain by Masked Men in Philippines : Crime: Attack in his home near Subic Bay base is believed to have been a robbery.

Two masked men fatally stabbed a U.S. Navy lieutenant in his home near the Subic Bay Naval Base in an apparent robbery, police said Sunday.

U.S. officials ordered all personnel restricted to the naval base immediately after the Saturday night attack, but they lifted the restrictions Sunday after determining the killing was not politically motivated.

Police identified the stabbing victim as Lt. Richard Brown, 33. No hometown was given.

Hundreds of Filipino troops drove through Communist-held neighborhoods in the city of Angeles on Saturday near the U.S.-run Clark Air Base in a show of force after U.S. troops were restricted to the garrison for security reasons.

The Philippine military also warned foreign aid workers to watch for terrorism. Five days ago, guerrillas suspected of belonging to the Marxist New People’s Army kidnaped a Japanese development official on the central island of Negros.

The provincial governor of Negros Occidental province on Sunday threatened military action to free the Japanese aid worker unless his abductors make contact with authorities soon.

Security has been stepped up around Subic, Clark and four other U.S. bases after the killing of three American servicemen in the past month.

In Olongapo, the base town near Subic, police said Brown was having a manicure in his apartment when the two assailants forced their way in around 10:45 p.m. Saturday.

The assailants, whose faces were covered with T-shirts, locked up three Filipino beauticians in a room, threatening to kill them if they resisted, police said.

Police said the suspects fled after ransacking the apartment. The beauticians managed to free themselves and found Brown’s bloody body in the dining room, police said. It was not known how much money or property was stolen.

Communist rebels oppose extension of the lease for U.S. bases, which expires next year.