MOSCOW (AP) _ A mental patient claiming to have a bomb hijacked an Aeroflot jet to Lithuania on Wednesday and demanded to meet with officials there, but he surrendered after the plane landed, officials said.

The Moscow man commandeered the Tu-134 while it was bound from the Soviet capital to Leningrad with about 70 people aboard, including some American tourists, news reports said.

Lithuania's internal affairs minister, Marijonas Misiukonis, said the hijacker wanted to help the republic by giving it the government-owned plane. Lithuania is involved in a standoff with the Kremlin over its declaration of independence March 11.

''Shortly after takeoff, he called the stewardess and claimed he had an explosive device in his lap, and pointed to paper wrapped around an object that he was holding tightly against himself,'' said Valery Akolsin, a spokesman for the Ministry of Civil Aviation.

The official news agency Tass quoted the hijacker as saying: ''Either we fly to Vilnius or I blow up the aircraft. I belong to the caste of immortals and have nothing to lose.''

''His request was complied with after the pilots consulted authorities on the ground and obtained permission to land the plane in Vilnius,'' Akolsin said. Vilnius is the capital of Lithuania.

Tass said the hijacker, identified as Igor Kalugin, demanded that a meeting be organized with an unidentifed aide to Lithuanian President Vytautas Landsbergis.

After the plane touched down it taxied to a remote section of the airport. Authorities drove up to the jet, and Kalugin, still clutching the parcel, surrendered, said a tower dispatcher quoted by Vilnius Radio.

Tass said he was taken into custody.

Akolsin said Kalugin was a registered patient at a psychiatric clinic in Moscow. Misiukonis also said Kalugin was registered in Moscow as being mentally ill.

Vilnius Radio reported that American, Japanese and Cuban tourists were among the passengers. They were taken to a special hall for foreigners at the airport while the jet was searched, the dispatcher said.

No explosives were found, and after about 90 minutes, the jet resumed its journey to Leningrad, the aviation ministry spokesman said.

The radio said Kalugin, 46 or 47 years old, was an employee of a Moscow theater and claimed to have acquaintances in Lithuania.

Misiukonis told Vilnius Radio that Kalugin did not put up a struggle when he was arrested and that no weapon was found.