WEST BERLIN (AP) _ East German leaders have been receiving death threats since the start of a sweep against leftist terrorists sheltered by the former hard-line Communist government, an official said Tuesday.

East Germany's interior minister said a tip from a former member of the country's now-disbanded Stasi secret police led police Monday to Henning Beer, 31, suspected in the 1981 bombing of a U.S. Air Force Base in West Germany.

Beer was the ninth suspected member of the left-wing West German Red Army Faction terrorist group captured since the sweep began on June 6.

It has been widely believed the secret police helped fugitive members of the Red Army Faction resettle in the East.

East Germany Interior Minister Peter-Michael Diestel said since the arrests began, his office has been receiving up to five anonymous death threat letters each day.

Diestel said the threats are aimed at him, Prime Minister Lothar de Maiziere and other officials.

Red Army Faction members often claim responsibility for their actions in the name of killed or imprisoned leftist terrorists.

There are believed to be several dozen active members and supporters of the Red Army Faction still at large.

In an interview with West German television Diestel said: ''We will continue to do our job.''

Interior Minister Dietmar Schlee of West Germany's Baden-Wuerttemberg state told reporters in East Berlin he fears reprisal attacks in West Germany as a result of the crackdown.

The Red Army Faction has been waging attacks against NATO, U.S. and West German industrial targets since the early 1970s. Among those killed were a U.S. soldier and leading West German bankers and industrialists.

The most recent victim, Deutsche Bank chief Alfred Herrhausen, was killed in a November bombing attack.

Terrorists claimed responsibility for the Herrhausen killing in the name of the ''Commando Wolfgang Beer.''

Wolfgang Beer, brother of the suspected terrorist arrested Monday night was a Red Army Faction member killed in a July 1980 automobile accident. Leftist radicals have claimed that authorities engineered his death.

Diestel said that harboring West German terrorists was the ''personal hobby'' of former Communist leader Erich Honecker and his ousted security chief, Erich Mielke.

Diestel said there were no indications the terrorists used East Germany as a base of operations for their attacks in West Germany.

Beer and fugitive suspected terrorist Silke Maier-Witt, 40, were both arrested Monday in Neubrandeburg, according to Diestel. He said that for the first time a member of the disbanded Stasi secret police give key information aiding in the capture, but provided no further details.

Both Beer and Ms. Maier-Witt had been living in East Germany under false names.

Diestel said he expects both to be tried in West Germany, along with the others recently captured.

In Karlsruhe, West Germany, a spokesman for the chief federal prosecutor's office said Henning Beer is suspected in the Aug. 31, 1981, bombing of Ramstein Air Base. That attack in West Germany seriously injured 17 people.

Helmut Pohl, a member of the Red Army Faction has already been tried and convicted of taking part in the Ramstein bombing.