A woman holds a styrofoam eagle with the picture of late President Lech Kaczynski prior to the ceremony of unveiling of the monument to the victims of the Smolensk air disaster, marking the eighth anniversary of the presidential plane crash near Smolensk at the Pilsudski Square in Warsaw, Poland, Tuesday, April 10, 2018. (AP Photo/Czarek Sokolowski)

WARSAW, Poland - Poland's ruling party leader unveiled a monument Tuesday remembering the victims of the 2010 airplane crash in Russia that killed President Lech Kaczynski, the first lady and many other political and military leaders, the worst tragedy to befall the nation in decades.

Thousands of Poles arrived from across the country to attend the Warsaw ceremony, part of the events marking the eighth anniversary of crash near Smolensk airport in Russia. Relatives of the 96 people killed took part in the unveiling ceremony.

Ruling party leader Jaroslaw Kaczynski, the late president's twin brother, said the black stone monument in the shape of plane stairs and bearing the names of the victims represents national dignity.

Official investigations have ruled the crash an accident, but Kaczynski alleges it resulted from foul play and has led to new investigations. Moscow has not yet returned the plane's wreckage or the flight recorders.

Kaczynski, 68, who leads Poland's conservative Law and Justice party, made it a priority to build a lasting memorial for his brother, but his efforts also provoked resentment.

Opposition politicians say the monument was not approved by Warsaw authorities, and that Kaczynski has used the crash victims to further his political goals.

Earlier in the day, the victims' names were read out loud during an emotional ceremony that started in front of the Presidential Palace at 8.41 a.m., the exact time of the plane crash on April 10, 2010.

Kaczynski laid a wreath in national white-and-red colours in front of a picture of his late brother and sister-in-law.

The couple's remains reside in a tomb at the historic Wawel Cathedral in Krakow. Their daughter, Marta Kaczynska, and Polish President Andrzej Duda laid wreaths there.

"So many people who were precious for Poland, who were the hope of Poland's politics and public life passed away that day," Duda said. "I don't think this loss can ever be compensated."

The victims were also commemorated in neighbouring Lithuania, where lawmakers observed a minute of silence for them.

News from © The Associated Press, 2018