The world began responding Friday to Mikhail S. Gorbachev's appeal for help in coping with the legacy of contamination that the Chernobyl nuclear power plant unleashed five years ago.

A television program focused nearly half of its newscasts throughout the day on help given by foreigners, including planeloads of aid expected from the United States, Britain and Germany.Gorbachev's wife, Raisa, attended a ceremony at which a Japanese foundation pledged equipment to help cope with the disaster's aftermath.

A radioactive cloud rose over the Soviet republics of Byelorussia and the Ukraine and moved quickly across Europe after the April 26, 1986, blast and ensuing fire in Reactor No. 4.

The Soviet government says the disaster killed 32 people: two immediately, 28 within three months and two more in the past five years. But some Soviet scientists and radical politicians in the Ukraine say the actual death toll was at least 250 and could be as high as 10,000.

Lawmakers in the Russian Federation and the Ukraine stopped their work for a minute of silence Friday to remember those who died, the state news agency Tass said. The Ukrainian legislators adopted a statement saying they were "doing everything in our power to protect the population from the accident's effects."

Soviet newspapers devoted several articles and commentaries to the anniversary, including an entire special supplement called "Lessons From Chernobyl" in the Communist Party daily Pravda.