A Polish court has given a communist-era interior minister a two-year suspended prison term for his role in the martial law crackdown in 1981.
The ex-minister, retired Gen Czeslaw Kiszczak, was sentenced in absentia.
Another defendant, former Communist Party leader Stanislaw Kania, appeared in the Warsaw court but was acquitted.
Kiszczak was found guilty of criminal association in the crackdown. Thousands of dissidents were arrested and as many as 100 people died.
Sentencing was delayed after a group of former anti-communist dissidents burst into the courtroom shouting "Free Poland!" and "Shame!". They were led by Adam Slomka, who heads the Confederation for an Independent Poland (KPN).
Poland's last communist leader and the man who proclaimed martial law in December 1981, Gen Wojciech Jaruzelski, was also put on trial for his role in the crackdown, but chronic illness prevented him from taking part.
The disruption caused by Mr Slomka and his associates on Thursday prompted the court to move to a smaller room and exclude the public, Polish media report.
Mr Slomka was punished with a 14-day jail term.