Tens of thousands of mourners have filled Warsaw's main square to pay tribute to Polish President Lech Kaczynski, his wife Maria, and the 94 other prominent Poles killed in a plane crash last week.
Sirens wailed at 8:56 a.m., exactly one week after the presidential jet crashed close to the Russian city of Smolensk, where the victims had been due to attend a memorial service for Poles killed in a World War II massacre.
On Warsaw's Pilsudski Square, a stage with a giant white cross displayed the black-and-white photographs of all the victims.
The names of the dead were read aloud to the mourners, who included Jaroslaw Kaczynski -- the president's twin brother and former prime minister -- and the presidential couple's only child, Marta.
Many in the crowd sobbed as a choir sang and soldiers fired three salvos in the air to honor the victims' memory.
"Our world went crashing down for the second time at the same place," acting President Bronislaw Komorowski said of the plane crash near Russia's Katyn forest, where thousands of Polish war prisoners were executed by the Soviet secret police 70 years ago.
Speaking at the memorial service, a stern Prime Minister Donald Tusk called the crash "the greatest tragedy in Poland since the war."
Among the dead were some of the country's top dignitaries, including the heads of all three armed forces, the governor of the central bank, the chairman of Poland's Olympic Committee, and several senior lawmakers.
Prominent Communist-era dissidents and relatives of the victims of the Katyn massacre were also onboard.
A state funeral for the president and his wife is set for April 18, but the travel chaos caused by a volcanic ash cloud hanging over Europe means many world leaders will not be able to attend.
U.S. President Barack Obama has canceled his plans to be in Krakow, along with demurs from India, Japan, South Korea, Mexico, New Zealand, and Pakistan blamed on the volcano's fallout.
compiled from agency reports