Polish President Lech Kaczynski and dozens of Polish dignitaries and politicians were among 97 people killed when the presidential plane crashed in western Russia on Saturday.

Russian and Polish officials said there were no survivors on the Tupolev, a Soviet-era plane. The president, his wife, Maria, and a delegation of Polish officials were on the plane for a one-and-a-half hour flight from Warsaw to attend ceremonies marking the 70th anniversary of the Katyn Forest massacre, when thousands of Polish officers were killed by Soviet secret police.

The crash has left huge gaps in the upper levels of the Polish political and military institutions. The President was joined on board by the army chief of staff, the national bank president, the deputy foreign minister, an army chaplain, head of the National Security Office, the deputy parliamentary speaker, a civil rights commissioner, at least two presidential aides and three lawmakers, according to the Polish foreign ministry.

Russia's Emergency Ministry said 97 people died in the crash, 88 of whom were from the Polish delegation. Piotr Paszkowski, Poland's foreign ministry spokesperson, said there were 89 people listed on the passenger list but one person had not shown up for the flight.

"We still cannot fully understand the scope of this tragedy and what it means for us in the future. Nothing like this has ever happened in Poland," Paszkowski said. "We can assume with great certainty that all persons on board have been killed."

Although there is no indication of foul play in the crash, which occurred at around 11 a.m. local time in Smolensk, the location and timing are laced with irony.

Former Polish president Aleksander Kwasniewski expressed shock and disbelief that the crash occurred near Katyn on the occasion of the massacre commemoration.

"This is unbelievable -- this tragic, cursed Katyn," Kwasniewski told Polish news station TVN24.

It is "a cursed place, horrible symbolism," he said. "You get chills down your spine."

Russian officials said air traffic controllers had asked the crew to divert from the military airport in north Smolensk because of fog and land instead in Minsk, the capital city of neighbouring Belarus, or in Moscow.

But the pilot disagreed. Although air traffic controllers generally have the final say in whether it's safe for a plane to land, they can leave the decision to the pilot's discretion. There are reports that the pilot made several attempts at a landing before the plane struck some trees on its approach and crashed.

Crash leaves holes in Polish government

In the Polish government, the president is commander in chief of the country's armed forces, but the domestic duties of the role are mainly symbolic. Kaczynski, 60, had been president since December 2005, when he defeated Prime Minister Donald Tusk in the presidential vote.

Associated Press reporter Jim Heintz said that although the crash results in a loss of expertise at the top levels of the Polish government and military, it is not likely to result in a constitutional crisis.

"It's the prime minister, Donald Tusk, who is the main administrator, so I think that once the shock wears off there's not going to be any considerable political disorder," he told CTV News Channel from Moscow Saturday.

Footage of the crash from Russian news stations showed pieces of the plane scattered among trees, with small fires burning in the foggy woods.

The Tupolev Tu-154 was at least 20 years old. There have been 66 crashes involving Tu-154s, including six in the last five years, according to the Aviation Safety Network. Officials in Poland have discussed replacing the planes that carry Polish leaders, but said they have yet to due to lack of funds. But the presidential Tu-154 had recently undergone a series of refurbishments and was believed to be well maintained.

Russian President Dmitry Medvedev moved quickly after the crash, promising to work closely with Poland on the crash investigation and sending his condolences to the Polish people.

"Russia shares the grief and mourning of Poland," Medvedev said in a statement posted on the Kremlin Web site. "Please accept the most sincere condolences to the Polish people, words of compassion and support to relatives and friends of those who perished."

Russian Prime Minister Vladimir Putin is in charge of a commission that will investigate the crash and was scheduled to arrive in Smolensk later Saturday where he will meet with Tusk, who is on his way to Smolensk from Warsaw.

Poland's parliamentary speaker, the interim president, declared a national week of mourning. Tusk called for two minutes of mourning at noon local time on Sunday.

In Poland, citizens and politicians responded to news of the crash with shock and tears. Mourners streamed into the square outside the presidential palace in Warsaw, lighting candles and placing flowers at makeshift memorials. The flag outside the palace was lowered to half mast.

International reaction

Messages of condolence for Poland were coming in from around the world as heads of state responded to the horrific crash.

U.S. President Barack Obama described the civilian and military leaders who died in the crash with Kaczynski as leaders who helped shape Poland's "inspiring democratic transformation."

Prime Minister Stephen Harper called Kaczynski's death a great loss for Poland.

"President Lech Kaczynski was a man who stood proudly and defiantly for democracy and human rights through even the most difficult times," Harper said in a statement.

Poland's ambassador to Canada said representatives from all of the main political parties were on the doomed flight, many of whom were his "close friends."

"So you can understand my feelings today," Zenon Kosiniak-Kamysz told CTV News Channel. "This is unbelievable, how tragic today is for us."

In spite of the devastating loss, he said the country's government will find ways to press on with its work.

"We'll be able to replace these many governmental functions," he added. "However, the situation is very complicated."

With files from The Associated Press and The Canadian Press