The communist government Tuesday announced a special parliament session would be held Aug. 31 to review its economic policies and said it would continue measures to stem the worst strikes since the 1981 imposition of martial law.

Authorities earlier announced a curfew Tuesday night on Jastrzebie, the city at the center of strikes that began a week ago and spread to coal mines, factories, ports and transportation facilities employing 100,000 people.Interior Minister Czeslaw Kiszczak, saying at least 20 illegal strikes have threatened anarchy in the country, announced Monday that law enforcement forces would secure major industrial facilities and that he had empowered provinces to impose curfews in the Katowice, Szczecin and Gdansk areas.

Government spokesman Jerzy Urban, who announced the date of the parliament meeting at a news conference Tuesday, said the session would consider the entire economic situation and perhaps make adjustments in national price and income policies.

Strikers have demanded higher pay and reinstatement of Solidarity, the outlawed independent trade federation.

Urban said there have been 49 detentions by police nationwide in connection with the strikes, most of them "preventative."

Solidarity leader Lech Walesa appealed again Tuesday for talks between authorities and his union.

"Solidarity remains steadfast in its search for dialogue despite the growing social tensions," he said on a tape brought out of the strikebound Lenin shipyard in Gdansk, where he spent the night. "The present situation in the country has become extremely serious. The just protest of the workers must not be ignored."

Urban told reporters talks with Walesa were impossible while strikes were going on.

New strikes began at two coal mines Monday night and there was a brief work stoppage Tuesday at the Nowa Huta steel mill near Krakow, authorities said.

The state-run news agency PAP reported that workers voluntarily ended a strike Tuesday at a railroad car factory in Wroclaw. Solidarity sources in Wroclaw said earlier that the strike was continuing.

Partial streetcar traffic resumed in the port city of Szczecin Tuesday after police dislodged strikers from depots Monday night.

In the first forcible action against strikers, riot police evicted scores from two streetcar depots and a bus depot Monday night in Szczecin, and strike leaders said more than 150 people were arrested.