Riot police crushed strikes at three southern coal mines and beat some men while dragging them away, activists said Thursday. Witnesses said 40 strikers at one mine escaped underground.

In the Baltic port of Gdansk, Solidarity leader Lech Walesa and 1,300 supporters spent Wednesday night occupying the strikebound Lenin shipyard, where Solidarity was born in 1980, said strike spokesman Bogdan Olszewski.The nine-day wave of strikes is the most serious to confront communist authorities since Solidarity was crushed in 1981. The strikers are demanding legalization of the independent union federation, higher wages and better working conditions.

Activists said strikes continued at seven mines in the coal-rich southern region of Silesia, in the Baltic port of Szczecin and at the Nowa Huta steel mill outside Krakow.

But state radio estimated that only a few hundred people were on strike at the Lenin shipyard and said one of five sections of the Gdansk port, Poland's largest, resumed work. Strikers did not confirm part of the port reopened.

Gdansk's port director issued an ultimatum that dockworkers would be fired unless they signed statements that they are not on strike by this afternoon, state radio said.

Police completely cleared strikers from the Borynia mine in Jastrzebie and the Morcinek mine in nearby Koszyce during the night, according to workers from both mines. All strikers were evicted from the nearby Moszczenica mine except 40 who managed to elude police and descended into the mine shaft with bread and lanterns, witnesses said.

The state-run news agency PAP, in a brief dispatch, said miners "left the mine" at Morcinek and also reported the strike ending at Borynia. It did not mention the Moszczenica mine.

"I was convinced the police would just try to intimidate us and not rush us, but it didn't turn out that way," said Francinek Cichon, a member of the Morcinek strike committee.

He said police detained Andrzej Andrzejczak, leader of the Morcinek strike committee, and beat at least six men at the Borynia mine.