As many as 70 Soviet military men, including a score of admirals and generals, may have been killed in the crash last week of a Soviet airliner near Leningrad, Western sources here said yesterday.

Reports of the crash in the Soviet news media said that the crash last Saturday killed two top admirals and a general, all commanders in the Soviet Pacific Fleet, but did not provide key details, such as how many died and how many people were on board.

The press reports identified three of the victims -- presumably the senior officers aboard -- as Adm. Emil N. Spridonov, 55, commander of the Pacific Fleet; Vice Adm. Vladimir D. Sabaneyev, 54, the fleet's top political officer; and Lt. Gen. Georgy V. Pavlov, commander of the fleet's air wing. oThe dead included "admirals, generals, officers, midshipmen, warrant officers and ensigns of the Pacific Fleet," the media reports added.

A Western diplomat, who asked not to be identified, said he had information that 22 to 24 admirals and generals had died. Western sources in the northern city of Lenigrad quoted Soviet officials as saying that the crash occurred about 12 miles outside the city and that up to 70 military personnel had perished.

Air crashes are normally not reported in the Soviet media, and it was believed here that the accounts of the crash in the press -- three days after it occurred -- were allowed because of the high rank of some of the dead and the protocol requirement of publishing obituaries.

The Soviet Union is estimated to have 2,000 to 3,000 generals and admirals in its armed forces. One Western military expert said the accident might cause "serious" short-term administrative problems for the Pacific Fleet but would not affect the fleet's fighting capability.

The officers of the fleet, which is headquartered at Vladivostok, may have been traveling to a meeting in Leningrad and was described in the Soviet press as called to "improve work among the top commanders and political personnel of the Navy."