The Soviet Union said today that "only 197 people were hospitalized" as a result of the nuclear power plant accident near Kiev over the weekend, apart from the two reported killed. It also said that radiation levels in the area were dropping and a cleanup was under way.

While Soviet officials attempted to portray the situation at the Chernobyl nuclear power plant as under control and returning to normal, western embassies here remained skeptical of the official statements, and several advised their citizens working or visiting in the area to leave.

As Soviet ambassadors in several Western European countries attempted to reassure those governments that the accident posed no serious threat, Western European leaders angrily chastized Moscow for its secrecy in the disaster and West German Foreign Minister Hans-Dietrich Genscher urged the Soviets to shut down all their power plants similar to the one at Chernobyl.

In President Reagan's first public comment on the accident, he told reporters in Bali, Indonesia, that the Soviets had been "clothed-mouthed." Officials with the president said that two U.S. offers of technical and humanitarian assistance had remained unanswered.

Wind shifts over Europe began bringing clouds of radioactive contamination, which earlier had affected Scandinavia, farther south today, with West Germany, Austria, Switzerland and Italy reporting radiation levels that were abnormally high but not considered harmful.

In Vienna, officials at the International Atomic Energy Agency said the Soviet Union finally had reported the accident but had not responded to the agency's offers of emergency help to cope with it.

Today's Soviet statement, buttressed by still pictures on Soviet television of what were said to be current scenes of the Chernobyl plant, clearly was intended to counter reports and speculation circulating in the West of a major disaster with the possibility of thousands of casualties.

"You can see for yourself there was no gigantic destruction and fires," a Soviet commentator said during a brief nationwide television broadcast tonight of still pictures showing what was said to be the exterior of the Chernobyl nuclear facility before and after the blast.

The second photograph, which showed the top of one building destroyed, was taken by a worker at the plant, the commentator said.

A senior Soviet nuclear official told British Ambassador Bryan Cartledge that the fire was out and that British exchange students in the area face no danger, diplomatic sources reported.

"Measurements being carried out by specialists using monitoring equipment show that no chain reaction fission of nuclear fuel is taking place," the Soviet news agency Tass said.

"Some news agencies in the West are spreading rumors that thousands of people allegedly perished," Tass said, but it repeated its statement of yesterday that there were only two fatalities. "Only 197 people were hospitalized," it continued, adding that 49 of them were discharged from the hospital after examination.

It said that "the radiation situation at the Chernobyl atomic power plant and in the adjoining locality is improving. The state of the air basin over the remaining territory of the Kiev region and the city of Kiev is causing no concern. The quality of the drinking water, as well as of the water in rivers and water reservoirs, is in line with standards.

"As a result of measures taken," Tass said, "over the past 24 hours the emission of radioactive substances has gone down and radiation levels in the area of the [plant] and the power station settlement have been reduced. . . . Work is under way to cleanse polluted areas of the adjoining locality.

"Enterprises, collective farms and state farms and institutions" in the area are functioning normally, it said.

Yuli Kvitsinsky, the Soviet ambassador to Bonn, told officials there that radiation released by the accident had contaminated areas north, south and west of the plant and that the authorities had evacuated people nearby.

A ham operator in the Netherlands said he had intercepted an amateur radio broadcast from the disaster area that spoke of "many hundreds" of dead and wounded and pleaded for international help, Reuter reported.

["You can't imagine what's happening here, all the death and fire. Please tell the world to help us," the ham operator quoted the message as saying. The authenticity of the report could not be confirmed.]

Today's subdued Soviet announcements and the rejection of western reports suggesting a widescale health calamity reflect a Soviet dilemma in coming to grips with the nuclear disaster, according to western diplomats in the Soviet capital.

On the one hand, the controlled Soviet reporting of what appears to be a major public health disaster contradicts official Soviet calls for media openness, the diplomats said.

On the other, the more details of the situation surface, the more it damages the Kremlin's image, they added.

The two-minute television report tonight was the most extensive official coverage of the incident since Monday evening when, after Scandinavian countries had detected alarmingly high levels of radioactive fallout and contamination of the atmosphere, an official statement acknowledged that a nuclear accident had taken place.

But public and private Soviet reports have still left key questions unanswered, such as the level of radiation, the number of people evacuated or what caused the disaster. Public statements have not even said when the accident occurred, but a Soviet Foreign Ministry official reportedly told the Finnish envoy here today that it happened on Saturday.

Western analysts here rejected the Soviet reports of low casualties and controlled radiation as an attempt to deceive Soviets and calm fears in the wake of what these analysts consider the worst nuclear accident in history.

The televised photograph of the plant showed "no apparent damage," a western scientific specialist here said. "I just don't believe it. It was meant to blunt a wave of local anxiety and camouflage a major disaster."

Western diplomats here said that up to 25,000 residents have been evacuated from the region.

A broad evacuation of westerners from the area began today amid concerns about long-term health hazards and suggestions in the West that a second reactor in Chernobyl may have begun a meltdown and expectations of long-term health hazards.

Austria, Finland and Britain were among the western countries recommending that their citizens leave the Chernobyl region, 60 miles north of the Ukrainian capital of Kiev.

An Austrian steel firm building a plant 160 miles from the reactor site flew 70 dependents of its workers out of the region today and ordered a work halt in the area.

Helsinki has offered the 100 Finnish students and workers in the Kiev area assistance in leaving, diplomatic sources here said. British students in Kiev boarded trains to Moscow tonight, sources said.

The U.S. State Department has warned against travel to the area, and U.S. tourists from Kiev have begun flooding into Moscow.

Four towns in the vicinity of the plant were evacuated, Tass said yesterday. The Soviets cordoned off an 18-mile radius surrounding the plant, West German construction workers there told Bonn's embassy here yesterday. The workers reported today that the region appeared calm.

But the Soviet Foreign Ministry has barred diplomats and foreign correspondents from the Chernobyl region.

Soviet officials also informed American networks here today that satellite transmission facilities would not be made available until after the May Day holiday, which ends Sunday.

Some of the western tourists who arrived in Moscow from Kiev today said they were advised against drinking water and eating fish, according to a western official who briefed them.

"There is an indication that there is water pollution," a western official based here said.