WARSAW, Poland (AP) — Polish police have filed charges against several people, including a prominent democracy activist from the Solidarity era, for obstructing a memorial observance for the late President Lech Kaczynski, who died in a plane crash in Russia seven years ago.

The crash occurred April 10, 2010, and on the 10th of every month Kaczynski's surviving twin brother Jaroslaw Kaczynski, chairman of the conservative ruling party, leads a memorial observance in Warsaw in honor of his brother and 95 others who died with him.

Protesters tried to block the observances and were removed by police Saturday evening. On Sunday, Warsaw police said they were charging Wladyslaw Frasyniuk with violating the bodily integrity of a police officer. Seven others are charged with "maliciously" obstructing a religious observance, and 10 with other offenses.