The head of Russia's top investigative body told Prime Minister Vladimir Putin today that a preliminary analysis of voice recordings finds no indication of any problem. He's also quoted as telling Putin that the recording reveals that the pilot had been told about difficult weather conditions, but decided to land anyway.
Regional officials had earlier said that Russian controllers had asked the Polish crew to pick another landing site because of heavy fog in the area.
Russia's transport minister says visibility was limited to 1,300 feet.
Another Russian official says 24 victims' bodies have been identified so far, but that it could be difficult to identify some of the others among the 96 people who died.
Poland's government moved swiftly Sunday to show that it was staying on course as tens of thousands of Poles expressed their grief over the plane crash in Russia that shocked the country.
New acting chiefs of the military were already in place and an interim director of the central bank was named Sunday, with work running as usual, said Pawel Gras, a government spokesman.
It was a rare positive note on a day wracked by grief for the 96 dead and laced with reminders of Poland's dark history with its powerful neighbor. The Saturday crash occurred in thick fog near the Katyn forest, where Josef Stalin's secret police in 1940 systematically executed thousands of Polish military officers in the western Soviet Union.
President Lech Kaczynski and those aboard the aging Soviet-built plane had been headed there to honor the dead.
Tens of thousands of Poles softly sang the national anthem and tossed flowers at the hearse carrying the 60-year-old Kaczynski's body Sunday to the presidential palace after it was returned from Russia's Smolensk airport, the site of the crash.
The coffin bearing the president's remains were met first by his daughter Marta, whose mother, the first lady, Maria Kaczynska, also perished in the crash. She knelt before it, her forehead resting on the coffin.
She was followed by Jaroslaw Kaczynski, the former prime minister, and the president's twin brother. He, too, knelt and pressed his head against the flag-draped coffin before rising slowly and crossing himself.
Standing sentinel were four Polish troopers bearing sabers. There was no sign of the twins' ailing mother Jadwiga, who has been hospitalized. The president had canceled several foreign trips lately to be by her side.
The coffin was placed aboard a Mercedes-Benz hearse and slowly traveled several miles to the palace, watched by thousands of weeping Poles.
"He taught Poles how to respect our traditions, how to fight for our dignity, and he made he made his sacrifice there at that tragic place," said mourner Boguslaw Staron, 70.
President Dmitry Medvedev declared Monday a day of mourning in Russia, and his country held two minutes of silence in memory of those killed in the crash.
Church bells pealed at noon and emergency sirens shrieked for nearly a minute before fading. Hundreds bowed their heads, eyes closed, in front of the presidential palace. Buses and trams halted in the streets.
No date for a funeral has been set and the Polish presidential palace has not yet said if Kaczynski will lie in state, though it is not a Polish tradition.
Kaczynski was the first serving Polish leader to die since exiled World War II-era leader Gen. Wladyslaw Sikorski was killed in a mysterious plane crash off Gibraltar in 1943.
Poland is a young democracy, adopting its constitution in 1997 after decades under communism, but political scientist Kazimierz Kik of Kielce University said he was confident it would remain stable.
"The democracy is passing the test, there is no doubt about it," he said. "This tragedy does not threaten the state in any measure, Poland's institutions are strong, but there is the trauma of the nation."
Among the dead were Poland's army chief of staff, the navy chief commander, and heads of the air and land forces. At the Field Cathedral of the Polish Army in Warsaw, hundreds gathered for a morning Mass and left flowers and written condolences.
Also aboard the aging Tu-154 plane were the national bank president, the deputy foreign minister, the army chaplain, the head of the National Security Office, the deputy parliament speaker, the Olympic Committee head, the civil rights commissioner and at least two presidential aides and three lawmakers.
Michal Boni, an official in the prime minister's office, said it remained in constant contact with the deputy head of the National Bank of Poland, Piotr Wiesiolek, who is acting director of the bank until a new one is appointed.
He said the bank's Monetary Policy Council will hold a meeting on Monday, as previously planned.
"We are prepared to make various decisions, but we do not see that anything dangerous could happen in the economy," Boni said. Poland's economy has so far managed to avoid recession.
The acting president, Parliament Speaker Bronislaw Komorowski, said he would call for early elections within 14 days, in line with the constitution. The vote must be held within another 60 days.
Kaczynski had indicated he would seek a second term in presidential elections this fall but was expected to face an uphill struggle against Komorowski and his governing party, the moderate, pro-business Civic Platform.
Kaczynski's nationalist conservative Law and Justice Party could benefit, however, from the support of a country mourning the loss of its president, particularly with elections now set to take place by late June.
The focus now turns to the investigation into the crash.
The head of Russia's top investigative body, Alexander Bastrykin, told Russian Prime Minister Vladimir Putin on Sunday that a preliminary analysis of the recording of the crew's conversations indicated the plane had no technical problems.
"The recording that we have shows that there had been no problem with the plane, that the pilot had been informed about difficult weather conditions, but still decided to land," Bastrykin told Putin, according to minutes of official meeting released by the Russian Cabinet.
In Warsaw, government spokesman Gras lauded the cooperation with Russian investigators and sought to tamp down fears that Poland was not being consulted in the case. He told reporters that Russian authorities waited until their Polish counterparts arrived before the black boxes were opened and analyzed.
The Smolensk regional government said Russian dispatchers had asked the Polish crew to divert from the military airport there because of the fog and land instead in Moscow or Minsk, the capital of neighboring Belarus.
Russia's Transport Minister Igor Levitin reported to Putin that the pilot had been warned about difficult weather conditions, with visibility limited to 400 meters (1,300 feet).
Vasily Piskarev, a deputy chief of Russia's top investigative body, said that 24 victims' bodies had been identified so far, most of them based on clothes and IDs. He said it could be difficult to identify some of the victims. Russian television stations showed grief-stricken relatives arriving in Russia to help identify the bodies.
Former Polish president, Solidarity founder and Nobel Peace Prize laureate Lech Walesa, said it was too soon to cast blame.
"Someone must have been making decisions on that plane. I don't believe that the pilot made decisions single-handedly," he told reporters. "That's not possible. I have flown a lot and whenever there were doubts, they always came to the leaders and asked for a decision, and based on that, pilots made decisions. Sometimes the decision was against the leader's instructions."
The Tu-154 was the workhorse of Eastern Bloc civil aviation in the 1970s and 1980s. Poland has long discussed replacing the planes that carry the country's leaders but said it lacked the funds.
According to the Aviation Safety Network, there have been 66 crashes involving Tu-154s in the past four decades, including six in the past five years. The Russian carrier Aeroflot recently withdrew its Tu-154 fleet from service, largely because the planes do not meet international noise restrictions and use too much fuel.
The Polish presidential plane was fully overhauled in December, its three engines repaired and updated with retrofitted electronic and navigation equipment.