U.S. servicemen traveling in unrestricted sections of East Germany have been beaten, shot at or rammed by Soviet vehicles in at least six violent incidents since 1980, culminating in Sunday's killing of an unarmed U.S. Army officer, Pentagon spokesman Michael I. Burch said today.

By contrast, Burch said, Soviet soldiers who recently were discovered taking photographs in restricted sections of West Germany were detained briefly by U.S. guards and then peacefully escorted back to their barracks.

Defense Secretary Caspar W. Weinberger, who is attending a NATO meeting here, pointed to the "totally different" ways in which Soviet and U.S. forces handled suspected intruders and told reporters that Sunday's shooting of Maj. Arthur D. Nicholson Jr. by a Soviet sentry was "a totally unjustified act" and "a very reprehensible thing."

In Moscow, the official news agency Tass published a formal statement charging that Nicholson was caught spying on a restricted Soviet military installation before being slain by a Soviet sentry as he tried to escape.

The Soviet account of the shooting described the incident and its "tragic outcome" as "regrettable" but said that "the entire responsibility for it rests fully on the American side," Washington Post correspondent Dusko Doder reported.

The statement also said there had been several previous "unlawful actions" by American servicemen, citing an August 1982 incident in which a Soviet officer allegedly was run down by U.S. military personnel in another restricted Soviet zone.

In Luxembourg, Weinberger, speaking to NATO defense ministers, reportedly said the incident reflects "a KAL mentality to shoot first and ask questions later." He was referring to the 1983 Soviet downing of a Korean Air Lines passenger plane.

Nicholson, 37, assigned to the U.S. mission in Potsdam, was shot to death while he and a sergeant were driving through East Germany. According to U.S. officials, Soviet soldiers prevented the sergeant from using his first-aid kit to treat Nicholson and delayed their own medical help while the major was dying.

Nicholson was monitoring Soviet military activities in accordance with a 1947 agreement permitting American soldiers to travel in East Germany except in restricted areas designated by the Russians.

Soviet officers are allowed the same latitude in West Germany.

Since 1980, however, U.S. soldiers traveling in unrestricted zones of East Germany have been "continuously pushed, shoved and generally harassed" by Soviet guards, according to Burch, who cited six episodes:

* On Jan. 30, 1980, an American serviceman suffered broken ribs after a car in which he was riding was rammed by a Soviet vehicle.

* On Oct. 10, 1980, American soldiers driving in a car were stopped by Soviet guards, pulled out and beaten.

* On May 19, 1982, U.S. servicemen were stopped in their car and were beaten while their hands were tied behind their backs.

On Feb. 28, 1983, U.S. soldiers in a car were shot at six times by Soviet guards. There were no injuries.

* On March 23, 1983, a U.S. vehicle carrying soldiers was rammed by a Soviet truck. Burch said he did not know of any injuries.

* On March 28, 1983, a Soviet officer fired warning shots at U.S. servicemen traveling either on foot or in a vehicle.

Burch said he did not know whether U.S. authorities had protested the incidents.

The spokesman said these acts differed from the restraint of U.S. guards on March 20 when they found three Soviet soldiers in a restricted quarter of Hof, West Germany, apparently trying to photograph a military installation from their car.

After holding the Soviets for a short time, Burch said, U.S. officers turned them over to local police who took them back to their Frankfurt base.

He said a similar incident occurred Jan. 25 during a NATO exercise when Soviet soldiers were caught taking pictures in a restricted U.S. Army sector near Frankfurt.

They also were were returned after a brief detention, he said.

"When we detained the Soviets, no force was used," Burch said.

Doder added from Moscow:

The tone and substance of today's statement suggested that the incident had placed the new Soviet leader, Mikhail Gorbachev, in an awkward situation and that Moscow was hoping it would not affect Soviet-American relations.

The detailed account appeared designed to lay out the Soviet case quickly and prevent the sort of adverse propaganda effects that followed the shooting down in September 1983 of the KAL plane.

According to the Soviet version of the incident, Nicholson and Sgt. Jessie Schatz penetrated the territory of a Soviet military installation near Ludwigslust, Schwerin District, despite "clearly visible warning signs" that access was prohibited.

Nicholson was described as "wearing camouflage gear" when he "secretly approached" a storage facility, "opened a window" and began taking photographs.

Meanwhile, the statement said, Schatz "remained in their vehicle and covered Nicholson's actions." The sentry spotted Nicholson and, acting in "strict compliance with military regulations," shouted at him in German and Russian to stop. "When the latter failed to comply and tried to flee, the sentry fired a warning shot in the air.

"Since the intruder did not stop even after this, the sentry had to use his weapon," the statement said. "He fired and killed the intruder."

Nicholson's action, the statement said, constituted a "flagrant violation" of the 1947 agreement "on the basis of which the U.S. mission in Potsdam functions." It said that Article 10 of the agreement "forbids the movement of members of missions in places where military units are stationed."

The Soviet Embassy in Washington, the statement added, had lodged a strong protest with the U.S. Department of State and demanded that the United States take "necessary measures to ensure strict fulfillment of the 1947 agreement" on allied military missions in Germany.

The statement charged that U.S. military personnel had carried out "such unlawful actions" on several occasions before. It cited an alleged incident in August 1982 when members of the U.S. liaison mission were spotted carrying out reconnaissance in a restricted Soviet military zone near Potsdam. In that incident, the statement alleged, the Americans "deliberately ran down a Soviet Army officer" and inflicted "grievous bodily harm to him."