Masked Intruders Kill 2 Men, Pregnant Girl : Violence: Two others are critically wounded. Police say that the slayings may be related to drug activity, but relatives deny the charges and call for peace instead of vengeance.

Four masked gunmen slipped into a Long Beach home through a back alley and opened fire on an extended family, killing two men and a pregnant teen-ager and critically wounding two others, authorities said Friday.

Police speculated that drugs were involved in the killings because there was a history of suspicious comings and goings at the home. A woman identifying herself as a family spokesman said the suggestion was untrue.

Roy Anthony Casillas, 25, his 17-year-old girlfriend, who was four months pregnant, and an unidentified man in his 30s were discovered Thursday around a back-yard pool table shortly after the 11:50 p.m. shooting.

All three died of gunshot wounds to their heads, Officer Bob Anderson said. The pregnant woman’s name was not released because her parents had not yet been found, Anderson said, and the man carried no identification.

Casillas’ brother, Kirk Robert Casillas, 23, was also shot in the head as he sat inside, watching television with his wife, Diana, 17. He remains in critical condition at Long Beach Memorial Hospital.

The fifth victim, Ronnie Henry Jr., 17, a friend of the Casillases, was pronounced brain-dead Friday but remained on life support at his family’s request so that his organs could be donated to others.

Two infants in the home were unharmed.

According to Anderson and witnesses, Henry, Roy Casillas, his girlfriend and the unidentified man were shooting pool in the back yard of the Casillas’ modest rented home in North Long Beach late Thursday.

What happened next was so sudden, according to neighbors, that nobody screamed. There were no shouts, no running. Neighbors and police described this scene:

Four men, wearing blue bandannas over their faces, walked into the back yard from the alley. Each was armed with a large-caliber handgun.

The gunmen shot all four people in the back yard at least once in the head. Then they moved inside, where Kirk and Diana Casillas were watching television.

One of the gunmen told Diana to turn her head, to look away. Then Kirk Casillas was shot in the head.

Diana Casillas was uninjured.

The gunmen escaped before police arrived through the alley.

Police said Friday that although no drugs had been found at the house, the number of visitors to the home led them to suspect there had been drug-related activity.

Neighbors in the 200 block of East 68th Street said many people came to the Casillas house, often stopping their car only to run inside for a minute and then leave. Most neighbors were concerned that drugs were being sold there.

A woman identifying herself only as Maria, who said she was a family friend and spokeswoman, responded: “The family would like to say there were no drugs involved. These were good boys.”

Rogelio Casillas, the father of Roy and Kirk Casillas, who lives across the alley, added: “No, no. They were both living with a wife or a girlfriend and their children. They were very responsible and wouldn’t fool around with that.”

Maria said the family had “one message to the friends of the victims: Please refrain from vengeance. Keep the peace.”