MOSCOW -- Millions of Soviets today began four days of mourning for President Yuri Andropov, whose death from kidney failure left the Soviet Union leaderless for the second time in 15 months and raised the possibility for a power struggle.
Andropov, 69, will be buried Tuesday.
His 455-day term of leadership ended with his death from kidney, heart and lung failure Thursday. A medical report disclosed he had been on dialysis for one year.
His body will lie in state in the white columned House of Unions a block from the Kremlin from today until Tuesday, the official Tass news agency said.
No official biography ever included references to his family, so the mourning period was expected to provide a view of survivors and resolve the question of whether he had a wife or was a widower.
The Kremlin flag dropped to half staff Friday and about 60 soldiers worked during the night to chip ice from the Red Square reviewing stand where dignitaries will gather for his burial.
President Reagan, who was vacationing in California, named Vice President George Bush to head the U.S. delegation to the funeral, ending speculation Reagan might himself go to Moscow.
Some lawmakers and administration officials had pressed Reagen to head the delegation as a gesture of conciliation toward the Soviets.
In Washington, Secretary of State George Shultz relayed Reagan's condolences to the Soviet Union and expressed the administration's readiness to work with Moscow to make the world a safer place.
There was no indication when a successor to Andropov would be named. The announcement could come any time after the selection process is conducted in secrecy among the 12 surviving full members of the ruling Politburo.
Their choice, whether one man or a collective leadership, will be submitted to the 300-member party Central Committee that will report the customary unanimous approval.
Konstantin Chernenko, 72, the rival who lost the struggle for Soviet Communist Party general secretary to Andropov after Leonid Brezhnev died in November 1982, emerged as a strong candidate for the Kremlin leadership.
The white-haired Chernenko, a Russian who rode Brezhnev's coattails into the Politburo, was named chairman of the funeral commission -- the same role Andropov assumed when Brezhnev died.
If Chernenko is passed over, at least half of his partners, have a chance to become the most powerful man in the world's largest country.
Other leading candidates were Mikhail Gorbachev, at 52 the youngest Politburo member, and Grigory Romanov, 60, whose power base is Leningrad, the country's second largest city.
Moscow party boss Viktor Grishin, 69, was considered by Western analysts as a possible compromise candidate. Geidar Aliyev, 60, of Azerbaijan, a Brezhnev and Andropov protege, was given little hope because he is not Russian.
Foreign Minister Andrei Gromyko, 74, and Defense Minister Dmitri Ustinov, 75, seemed unlikely to claim the party leadership but were certain to have a large role in determining the winner.
Andropov died after a six-month public absence during which the only explanation provided by the secretive Soviet government was that he had a cold. But Tass moved a medical report saying Andropov had suffered from kidney disease, high blood pressure and diabetes.
'From February 1983, in connection with the discontinuance of the function of the kidneys, he remained on treatment with hemodialysis ('artificial kidney'),' the statement said.
The treatment enabled him to work until the end of January when his internal organs suffered a massive collapse of function, the statement said.
A party-government resolution decreed that gun volleys be fired in Moscow, provincial capitals and other cities on Tuesday when Andropov is laid to rest. Work in all factories and shops will cease for five minutes and trains and sea vessels will blow their whistles for three minutes. Schools will be closed.
In a show of unity and signal to the West, the party and government issued a statement late Friday vowing to continue Andropov's policies of 'strengthening peace' and 'giving a firm rebuff to the aggressive intrigues of imperialism.'
The lowest point in U.S.-Soviet relations during Andropov's rule came on Sept. 1, 1983, when the Soviets shot down a Korean Air Lines Boeing 747 that strayed into Soviet airspace during a flight from New York to Seoul, South Korea. The incident claimed 269 lives, including 62 Americans.