SMOLENSK, Russia -- The crash of an aging Russian airliner ravaged the top levels of Poland's military, political and church elite Saturday, killing the Polish president and dozens of other dignitaries as they traveled to a ceremony commemorating a slaughter that has divided the two nations for seven decades.

Poles wept before their televisions, lowered flags to half-staff and taped black ribbons in their windows after hearing that President Lech Kaczynski and the upper echelons of the establishment lay dead in woods a short drive from the site of the Katyn forest massacre, where 22,000 Polish officers were killed by Soviet secret police in one of Poland's greatest national traumas.

Thousands of people, many in tears, placed candles and flowers at the presidential palace in central Warsaw. Many called the crash Poland's worst disaster since World War II.

Twenty monks rang the Zygmunt bell at Krakow's Wawel Cathedral -- the burial spot of Polish kings -- a tolling reserved for times of profound importance or grief.

The crash also shocked Russia. Sensing the depth of the tragedy for Poland, Prime Minister Vladimir Putin personally took charge of the investigation and very quickly and publicly offered condolences, along with Russian President Dmitry Medvedev.

"On this difficult day the people of Russia stand with the Polish people," Medvedev said, according to the Kremlin press service.

Chunks of the plane were scattered widely amid leafless trees and small fires in woods shrouded with fog. Early indications pointed to pilot error in heavy fog as a factor in the crash, officials said.

On board were the national bank president, deputy foreign minister, army chaplain, head of the National Security Office, deputy parliament speaker, Olympic Committee head, civil rights commissioner and at least two presidential aides and three lawmakers, the Polish foreign ministry said. Kaczynski's wife, Maria, also died.

"This is unbelievable -- this tragic, cursed Katyn," Kaczynski's predecessor, Aleksander Kwasniewski, said on TVN24 television.

It is "a cursed place, horrible symbolism," he said. "It's hard to believe. You get chills down your spine."

Polish Prime Minister Donald Tusk and some Cabinet members flew to Smolensk from Warsaw. The president's twin brother, former Prime Minister Jaroslaw Kaczynski, headed to the area in a chartered plane along with party members.

Television showed Jaroslaw kneeling and praying at the crash site. Tusk, joined by Putin, placed a wreath at the site and knelt. When he stood up, Putin hugged him.

The Polish military suffered the deepest losses. Among the dead were the army chief of staff, the navy chief commander, and heads of the air and land forces, who were all making the emotional trip to honor the Polish officers slain by the NKVD, the acronym for the Soviet secret police at the time of the killings in 1940.

Some on board were relatives of the officers slain in the Katyn massacre. Also among the victims was Anna Walentynowicz, whose firing in August 1980 from the Lenin Shipyards in Gdansk sparked a workers' strike that spurred the eventual creation of the Solidarity freedom movement.

"This is a great tragedy, a great shock to us all," former president and Solidarity leader Lech Walesa said.

Polish Parliament Speaker Bronislaw Komorowski, who became acting president, addressed his country on television: "Poland is in mourning, we have suffered a dramatically painful loss."

He said he would announce early elections within 14 days of the president's death, in line with the constitution. The vote must be held within another 60 days.

Russia's Emergency Ministry said there were 97 dead, 88 in the Polish state delegation.

In the village of Gorzno, in northern Poland, the streets were largely empty as people stayed home to watch television.

"It is very symbolic that they were flying to pay homage to so many murdered Poles," said resident Waleria Gess, 73.

Kaczynski, 60, was the first Polish leader to die in office since exiled World War II-era leader Gen. Wladyslaw Sikorski died in a mysterious plane crash off Gibraltar in 1943.

The president was a conservative and a lifelong skeptic of Russia with many detractors at home and abroad. Condolences from world leaders paid tribute to his patriotism and defense of freedom during Communist rule in Poland.