The Soviet government announced tonight that six persons "suffering from burns and radiation died" as a result of the Chernobyl nuclear accident, making it the world's first nuclear power plant accident with officially reported radiation deaths.

Thirty-five persons injured at Chernobyl are in "grave condition," according to the Council of Ministers statement published tonight by the Soviet news agency Tass and read on the televised evening news. The last official status report on the injured on May 1 listed 18 of the 200 victims in "serious" condition.

In an indication of largescale bungling of the mass evacuations after the April 26 Chernobyl accident, three local officials have been reprimanded for mishandling the evacuation of workers and their families, the Soviet Communist Party newspaper Pravda reported today. It was the first announced disciplinary moves against personnel connected with the nuclear facility, situated 80 miles north of Kiev.

The 35 gravely injured, hospitalized in Moscow, are "undergoing therapeutic and preventive treatment," the statement said. According to Soviet sources, an unspecified number of the Chernobyl patients have had bone marrow transplants -- standard medical treatment for radiation victims.

An international team of physicians, including U.S. marrow specialist Robert Gale and three other American doctors, have conducted the operations, Soviet sources said. The Americans have said they are working under strict conditions of confidentiality.

Tonight's statement left unclear whether the total Chernobyl death toll is now six or eight. The last official casualty report -- released April 29 -- listed two dead, and Soviet authorities later said they had been killed by falling debris and steam burns.

During the past 24 hours, the statement said, "work was considerably broadened" at Chernobyl "to clean up contaminated sections of the territory and structures of the station." It added that "an effective cooling of the damaged reactor is under way."

The statement said the radiation situation in Kiev and in the rest of the Ukraine and neighboring Byelorussia "is improving."

A report from Chernobyl on the Soviet evening news featured a helicopter crew rehearsing dropping cargoes on the damaged reactor. Since the accident, a commentator said, hundreds of loads of sand, boron and lead have been dropped from a height of 1,000 feet in an effort to smother the radiation emissions.

The telecast also showed workers taking radiation tests by helicopter.

Farm work is proceeding outside of the closed 18-mile zone surrounding the damaged reactor, the official statement said. "Factories are functioning normally," it said, "and tourist tours are being conducted by the usual itineraries."

Three leaders of a transport combine attached to the Chernobyl plant were reprimanded for doing nothing to help the 200 evacuees from their firm or their families, Pravda reported.

"Wages were not given out on time, clothing was not handed out, they ignored the evacuees' legitimate requests," Pravda said.

One of the officials, charged with showing "complete indifference" to the fate of the evacuees, was expelled from the party. Another was strongly reprimanded. All three were mentioned by name in strongly worded criticisms in the party newspaper.

Some leaders of the evacuation, Pravda said, turned out to be "psychologically unprepared" for work in the conditions caused by the Chernobyl accident.

The Pravda article gave the first indication of official dissatisfaction with the evacuation, but focused only on the handling of the 200 transport workers.

Indications are, however, that the beginning of the entire evacuation was so delayed that additional lives were put at risk, and that as late as a week after the initial incident, senior Politburo members ordered increased evacuation efforts.

The original tally of 49,000 evacuees, given by Moscow party chief Boris Yeltsin a week after the accident, has been updated twice in Soviet reports: last week to 84,000, and yesterday to 92,000.

In a Moscow press conference last week, Soviet officials praised the evacuation, but indicated that it began 36 hours after the explosion.

During that period, people in the Chernobyl area were exposed to additional radiation, increasing chances of a higher death toll, according to western analysts here.

After a May 2 visit by Prime Minister Nikolai Rhyzhkov and Politburo official Yegor Ligachev to the Chernobyl area, additional precautionary steps were taken including the evacuation of the town of Chernobyl, according to western diplomatic sources. Previous Soviet press reports had said those evacuated were given close medical attention, accommodation and basic necessities.