The arrest of 11 FALN members near here apparently has shattered the leadership of the Puerto Rican terrorist gang, which has claimed responsibility for more than 100 bombings in U.S. cities, including Chicago, New York and Washington, and in Puerto Rico since 1975, authorities said today.

Authorities said they believe not more than a dozen top members of the terrorist gang remain at large. However, they added that it is difficult to determine the size of the gang, which also appears to have a number of sympathizers. FALN stands for Fuerzas armadas de Liberacion Nacional (Armed Forces of National Liberation).

The group's members allegedly have been threatening delegates supporting President Carter in Chicago and other cities the Chicago Sun-Times reported today. The FBI had been taping the telephones of the delegates in an effort to track down the terrorists.

Investigators alleged that names, telephone numbers and addresses of the Carter delegates apparently were obtained by the FALN in its hit-and-run raid on the Carter campaign headquarters in Chicago March 15. The same day, the FALN also raided Republican George Bush's headquarters in New York City.

One of the Carter delegates said she received a telephoned death threat from a purported FALN member by two days after she was elected. "He told us I was going to get it, that all the Carter delegates were going to get it [and added] 'Watch out for the bomb.'"

The five women and six men were arrested Friday in Evanston, a suburb just north of Chicago, after an armed robbery in which a large truck was stolen from a rent-a-car office in Evanston.

Police had spotted the truck parked near the campus of Northwestern University and arrested two persons as they entered the truck. And the same time police received calls that nine persons were acting suspiciously around a van that was parked nearby.

Police rushed to the scene and arrested the nine. The suspects were wearing jogging suits, apparently in an effort to blend into the neighborhood, which is close to a park that runs along Lake Michigan. Witnesses reported that the group had been entering and leaving the van for some time.

All told, about 20 firearms, the stolen truck, two vans ans two cars were seized.

The eleven suspects were charged with a variety of local weapons, theft and armed robbery charges. Bond for each was set at $2 million and a preliminary hearing was scheduled for Monday morning. They remained in jail today, under heavy guard.

Two of those seized were identified as Carlos Alberto Torres, 27, the reputed leader of the FALN, who was number one on the FBI's 10-most-wanted list, and his wife, Marie Haydee Torres, 25, who also was on the FBI list. Also being held were Ida Luz Rodriguez, 29, Dylcia Noemi Pagan, 33, Elizam Escobar, 31, and Fred Mendez. The remaining five suspects had not been positively identified, and continued to refuse to give their names.

Carlos Torres, a minister's son and former Boy Scout, had been on the FBI list since 1976, when authorities discovered a bomb factory containing more than 200 stacks of dynamite in his Chicago apartment. Torres had been indicted by a federal grand jury in Chicago in connection with the planting of 16 bombs in Chicago from 1975 to 1977.

Marie Torres has been indicted in New York for the August 1977 bombing of the Mobil Oil Corp. building that killed one person.

Carlos Torres' father, the Rev. Jose A. Torres, pastor of the First Congregational Church of Chicago, visited his son in jail Saturday. "I have always been very proud of my son," the elder Torres said afterward. "I don't believe anything that has been said of him until it has been proven. I respect him and the cause for which he stands."