A nuclear reactor at the Chernobyl nuclear power plant, site of a disastrous 1986 explosion, was shut down Monday because of a malfunction, Izvestia reported. The government newspaper, in a report attributed to Nikolai Shteinberg, deputy chairman of the State Committee for Nuclear Power Station Safety, said the staff of Reactor No. 3 shut down the unit ``in keeping with operational rules.'' ``Established safety standards were not violated,'' the newspaper said. It gave no further details on the malfunction. It was Chernobyl's Reactor No. 4 that caught fire and exploded on April 26, 1986, spewing radioactive cesium, strontium and plutonium over a wide area of the Ukraine, Byelorussia and Russia. Official reports say 31 people were killed in the partial meltdown, but unofficial reports say 250 died. Four years after the accident, more than 2 million people are still living on contaminated lands in the region.