Authorities searched Friday for clues in the killing of three Iranian-born Jewish men who were shot in a West Hollywood apartment.

The victims, including two brothers, were killed shortly after 9 pm Thursday, and their killer or killers got away without anyone seeing them, sheriff's Detective Bill Marsh said.

The coroner's office identified the victims as Pirooz Moussazadeh, 27, his brother, Shahriar Moussazadeh, 38, and Bernard Khalili, 27.

Residents of the Kings Road Arms apartments building heard what they thought were firecrackers going off. They called the apartment manager, who went to investigate and found the door open and a body inside.

Deputies found two more bodies in the apartment. All three men were in different places in the open-plan unit. No weapons were found, and there were no immediate clues as to why the men were targeted, authorities said.

At least two of the men lived in the apartment.

Marsh said the men likely knew whoever killed them. There was no sign of a struggle, and the door had not been forced open.

All three victims were members of the Iranian Jewish community and moved to the US as young children, said Pooya Dayanim, president of the Iranian Jewish Public Affairs Committee.

"These are three guys who happen to be Persian Jews who happen to have been murdered," Marsh said.

The victims were not wealthy, and family members told him they had no criminal pasts, Dayanim said.

"The only thing that sticks out is there was nothing significant about them," he said.

The Los Angeles Times reported Friday that the killings were the second tragedy to hit the Khalili family in less than two years. In 2008, Bernard Khalili's sister, Bianca Khalili, fell to her death from a Century City high-rise. Authorities ruled it a suicide.

A cousin, who was not named, told the Times Bernard Khalili was like a brother to him.

"My cousin was always a very kind person," he said. "A very forgiving person."

The apartment building was said to be generally secure and peaceful. Investigators were seeking to speak with anyone who may have seen or heard anything.

West Hollywood is northwest of downtown Los Angeles.