The embassy said two of the murdered foreigners visited the Chameleon night club.

The U.S. Embassy is urging Americans to "exercise caution" after four foreigners and four Russians were killed in the past two years, apparently after picking up someone from a gay club in Moscow.

The embassy has pushed prosecutors and police to reopen the cases and determine whether the murders are linked, but with no success so far. U.S. General Consul James Warlick said Wednesday he has asked the Foreign Ministry to step in.

The embassy issued the warning on Jan. 3 in a warden message, which was distributed by e-mail to Americans living in Moscow. The sense of urgency, however, comes through more clearly in a cable -- labeled sensitive but unclassified -- that it sent to the U.S. State Department on Dec. 1.

"Comparing notes with consular officials from other foreign missions, we believe we may have uncovered a disturbing pattern of murders of foreign gay men in Moscow," said the cable, which was first obtained by The Washington Blade, a gay publication in Washington, and then by The Moscow Times.

"Even if these murders are not connected, we believe that they suggest a sufficient level of danger for gay AmCits traveling to and residing in Russia that we should find a way to share this information with the AmCit community," it said.

At least one of the victims had been at the Chameleon club the night he was killed, and another was known to frequent the club, the cable said. Three of the four foreigners were found stabbed multiple times in their apartments and robbed, it said.

Some members of the gay community in Moscow are convinced the murders are connected and that the Kazarma club, which is housed inside the Chameleon club, is the link.

The first of the four foreigners to be killed was British citizen Christopher Rees, in September 1999. The Moscow Times reported at the time that Rees, 34, who worked as a television producer for CTC television, was found stabbed to death in his apartment on Tverskaya Ulitsa. His co-workers had become alarmed when he failed to meet his driver downstairs.

Steve Malcom, an American, was the next to be found dead, on Aug. 27, 2000, also of multiple stab wounds. The Associated Press reported that he was a 49-year-old teacher and had been dead for six days when police found his body in his apartment. Audio and video equipment had been stolen.

In February 2001, Australian citizen Thomas Nagy-Bachman was found stabbed to death in his apartment, the cable said. Police at the time described him as an Austrian and said the body was found in March. He was working in Moscow as an independent petrochemical consultant and had previously worked for Alfa Bank.

According to the cable, the newspaper Moskovsky Komsomolets reported in November that police had arrested a suspect in Nagy-Bachman's death -- a soldier from Kursk who prostituted himself for money.

The fourth foreign victim was German. On June 23, 2001, "Heinrich-Helmut Kurth was beaten to death so brutally as to render his face unrecognizable after leaving the Chameleon club," the cable said. "Rees was also known to frequent this club."

Kurth, 40, who worked as a chef at the Sheraton Palace Hotel, was found on the street, on Bolshoi Tishinsky Pereulok, and was taken to the hospital, where he died of massive head injuries. Police at the time said he was killed in an apparent robbery.

After consulting with consular officers at other embassies, U.S. officials said they decided several months ago that the cases could be connected and approached the gay community in search of more information.

"As we began to dig and spoke informally to contacts in the gay community, we realized that it wasn't an isolated incident and that there have been four Russian gay men killed during the same period," an embassy official said Wednesday.

"Anecdotally we know that the murders may be connected to the club scene. Right now we can't say that it's one specific club or that they're all linked, but we've been trying to find out."

The U.S. Embassy has urged the Prosecutor General's Office to look into the murders.

"The prosecutor told us that the Malcom case had been dropped in the absence of further leads, but thanked us for passing along the information. ... The German Embassy has been told that its case has been dropped as well," the cable said.

Telephoned on Wednesday, the Prosecutor General's Office said it would have some information on the cases soon.

The embassy official said the police were also asked to reopen the Malcom case, but a couple of weeks ago they sent a letter saying they had looked into the various murders and found no link.

A spokesman for the British Embassy refused to comment on any specific case, saying only that "any murder of a British national is taken most seriously."

A spokesman for the German Embassy said, "We are trying to widen our database of murder cases of foreign homosexuals before making a conclusion. ... If, after a lengthy investigation, the Russian authorities declare that there is not a connection, we will accept their conclusion."

Calls to the Australian Embassy were not returned Wednesday.

While once a gay club, Chameleon, which is located on Presnensky Val, is now considered straight. But inside Chameleon is the gay club Kazarma. According to the web site listings of Afisha, Moscow's leading Russian-language entertainment magazine, Kazarma is considered the top gay hangout in the city, with naked young male students from Moscow circus schools dancing on stage and the availability of private cabins.

It also has a reputation for being downright menacing.

"To the best of my knowledge all the murders were connected to Kazarma," said Nikita Ivanov, international editor of Russian gay and lesbian web site Gay.ru, which has posted a warning against going to the club.

"It's not your regular kind of gay club," he said Wednesday. "It is an inherently dangerous place. The kind of people who congregate there are like hustlers, male prostitutes from the provinces and bad neighborhoods of Moscow."

Gay.ru has received no reports of violence at other gay clubs, he said, but has received more than a dozen reports about robberies in front of or in the immediate area around Chameleon and about murders connected to it.

"My suspicion is that the motive behind these crimes is economic," Ivanov said. "They're committed by some poor boy from the provinces who has ended up in Moscow a criminal and prostituting himself."

Tamara Zhikhareva, Chameleon's financial manager, recalled one case two years ago when a regular foreign customer had been killed in his apartment and police had questioned the club's personnel. She said she could not remember the name of the customer and refused to say whether the victim had picked up his partner in the club.

Zhikhareva said Chameleon has become quieter since it shifted away from catering to a gay clientele a year ago.

"Today it is a safe place where all clients have to pass through strict face and passport control," she said in a telephone interview. "As for the foreigners, they enjoy special treatment -- our guards keep an eye on them so that nobody extorts money from them."

The Kazarma club also is undergoing a transformation, she said. "Kazarma is dying now," Zhikhareva said. "This year it will be reoriented to a regular youth club."

Ivanov, however, said he has received complaints from expatriates that the security men at Kazarma turn a blind eye to crimes against foreigners or actually point out foreigners to the perpetrators.