The FBI issued an alert in New Hampshire early Tuesday morning for two men and one woman wanted for questioning in connection with Monday's bombing of the U. S. Capitol.

The trio were reported to be traveling in a car owned by Judith L. Clavir, who shares a Cambridge apartment with Yippie leader Jerry Rubin and another person.

Rubin-who has been in Berkeley, Calif, since February 21-was surprised when told of the alert last night.

The New Hampshire State Police reported yesterday, however, that the FBI had cancelled the alert.

Rubin Scoffs

Neither Rubin nor Clavir has been named as a suspect by the FBI. The FBI has refused to comment on its investigation of the bombing, but the Massachusetts Registry of Motor Vehicles said yesterday the car described by the FBI belongs to Clavir, who lives at 502 Green St.

"The FBI probably thought they would try to indict us because they can't catch any of the Weathermen," Rubin said. "Well, where can I go to apply for an indictment?"

Rubin said he knows nothing about the bombing but added that he "confessed to everything."

The FBI alert instructed New Hampshire State Police to "use caution and hold [the trio]." The alert also said the occupants of the car "may be in possession of explosive materials."

The Associated Press and the New York Post received letters Monday signed by the "Weather Underground" claiming credit for the bombing. The letter said, in part, "We have attacked the Capitol because it is a . . . monument of U. S. domination over the planet."

Congress remained in session yesterday despite more than a half dozen bomb threats. Several other federal buildings received threats but only one was evacuated.