Former Solidarity leader Lech Walesa testified Wednesday at a trial of Polish communist-era chiefs accused of ordering a 1970 massacre, taking the stand against the general who once jailed him.

General Wojciech Jaruzelski, who would later declare martial law in an attempt to stamp out the Solidarity labor union, was Poland's defense minister when security forces killed 44 shipyard workers on the Baltic coast during food-price protests.

"We must judge them so nobody in the future will do something similar," Walesa told reporters outside the Warsaw courtroom. "On the whole, he's guilty in some way, but political factors counted back then."

Jaruzelski, 85, has pleaded innocent, saying he never gave orders to fire on the demonstrators. He and five other defendants could get up to a life sentence if found guilty.

The trial, now in its seventh year, has faced delays as Jaruzelski's lawyers wanted more time to look over evidence. Jaruzelski has skipped part of the proceedings for health reasons.

No former communist leaders have been brought to responsibility for the crackdown.

Walesa told the court he tried to pacify the crowd by promising to win the release of communist-held prisoners, news reports said. When security forces attacked the crowd anyway, workers called Walesa a traitor and began hurling stones.

Before the session, Walesa declined to say whether he wanted to see Jaruzelski in jail. He said he offered Jaruzelski his hand in greeting, "like a corporal to a general."

Jaruzelski watched the testimony through a pair of darkened glasses he wears because of his sensitivity to light. He had no questions for Walesa during the two-hour testimony.

Jaruzelski is also due to go on trial in September for his role in declaring martial law in 1981 communist Poland.

He faces 10 years in prison if found guilty of directing the effort that suppressed thousands of Solidarity activists - many were arrested without charge - and killed as many as 100 people.

Jaruzelski, Poland's last communist leader, claims he had to declare martial law to avoid a Soviet invasion and that his decision saved Poland from catastrophe.

In the 1981 crackdown, he banned Solidarity and had Walesa and other union leaders arrested.

Jaruzelski was later forced to negotiate with Solidarity after strikes broke out nationwide. He resigned as Poland's leader and was replaced by Walesa, who became Poland's president in 1990 in the country's first democratic elections.