LOS ANGELES, JULY 18 -- A 31-year-old Guatemalan immigrant has told Los Angeles police she was kidnaped for four hours Friday night and questioned about her work with Salvadoran refugees. It was the latest in a series of incidents here suggesting an outbreak of Central American terrorism.

Los Angeles Police Lt. Dan Cooke said his department is investigating the gunpoint abduction of Anna Maria Lopez and its possible connection to the July 6 rape-torture of a Salvadoran woman and a spate of threatening letters and telephone calls to activists opposing U.S. aid to the army of El Salvador.

Shortly before the Friday kidnaping, the Federal Bureau of Investigation announced it had also begun to investigate "the possibility of terrorist activity" in Los Angeles.

"It's pretty outrageous, the stuff that is going on there," said Beth Perry of the national office of the Committee in Solidarity with the People of El Salvador (CISPES). Several groups here supporting talks between the Salvadoran government and Marxist rebel forces today again denounced the incidents as an invasion of right-wing Salvadoran "death squads" into the United States.

Lopez told police she was forced into a late-model two-door Toyota at about 8:30 p.m. Friday after getting off a Hollywood Freeway bus to attend a meeting at the First Unitarian Church.

Two men wearing masks and speaking with what appeared to be Salvadoran accents questioned her repeatedly about her work with a Guatemalan cultural group and told her to refrain from any connections with Salvadoran activists, police and activist group leaders said. Lopez was let off unharmed in Pomona, about 25 miles east of where she was abducted, and called police about 1 a.m.

CISPES and the Southern California Ecumenical Council's Inter-Faith Task Force on Central America have reported several other incidents in the past two weeks. After a Salvadoran woman working with CISPES reported being interrogated, tortured and raped in a van July 6, activists here said they received a list of persons marked for death by right-wing forces here.

One of the Salvadoran women on the list, whose name had not been released, said she received two identical death threats on her answering machine. According to tapes of the calls played at a Friday news conference, the caller said in Salvadoran-accented Spanish: "For being a communist, we will kill you."

At the same news conference, the Rev. Luis Olivares, pastor of the city's largest Latino parish, said that on Wednesday he had received a letter similar to those sent to some of the 14 priests alleged to have been killed by death squads in El Salvador. The letter contained one sheet of paper with the initials "E.M." and the numeral 1. The initials appear to stand for the Escuadron de la Muerte (Squadron of Death), a name used by rightest terrorist groups in El Salvador.

Lt. Cooke said police investigators see "a very strong possibility" that the incidents are linked, and that they reflect activities of Salvadoran terror groups. The department's antiterrorism division had joined the investigation.

After initially saying it was not involved in the probe, the local FBI office released a statement Friday saying it "has opened an investigation into allegations of possible 'El Salvador death squads' operating in the Los Angeles area" reflecting "the possibility of terrorist activity."