A defiant Berisha called Prime Minister Fatos Nano "the champion of corruption in Europe" and led an opposition protest rally of about 2,000 Democratic Party supporters in the capital, Tirana.
Berisha, who could be arrested on charges of seeking to overthrow the government if he loses his immunity as a member of parliament, called Thursday for nationwide protests Friday, saying they would be peaceful.
Before the rally, he called Nano "the most dangerous leader, staying in power only by arresting, by murdering, by executing...the opposition."
He accused Nano's secret police of cutting off access in Albania to independent media, forcing people to rely on state media, which he claims is sending out false, biased information. He said Albanians must listen to foreign or independent media in order to understand what is going on.
"Fatos Nano is keeping the Albanians in darkness," he said.
Nano's elected government is backed by Western powers desperate to prevent the unrest from influencing other crises in the region, mainly the violence in neighboring Kosovo province in the Yugoslav republic of Serbia.
The crisis raised fears of nationwide unrest reminiscent of the months of anarchy that struck Albania last year following the collapse of shady pyramid schemes that cost many people their life's savings.
A parliamentary committee convened Thursday to consider whether to lift Berisha's immunity. It was unclear when a decision would be made.
A source who asked not to be identified said there was pressure from international officials to come up with a lesser charge against Berisha in order to avoid further instability.
Meanwhile, new unrest was reported in northern Albania, where Berisha has strong support.
Police said about 80 people armed with grenades and automatic rifles attacked a bank and police station late Wednesday night in Lezha, 35 miles north of Tirana. Three of the attackers died and several were wounded, said Interior Ministry spokesman Artan Bizhga.
An explosion in Lezha two weeks ago damaged the office of Nano's Socialist Party.
In rioting Sunday and Monday, Berisha's supporters damaged the parliament and prime minister's office, briefly took over the state television station, burned cars, and looted shops.
The second major crisis in Albania in 18 months began after the slaying Saturday of popular politician Azem Hajdari, a close aide to Berisha, who immediately blamed Nano.
Demonstrations degenerated into rioting that lasted two days and left three people dead and dozens injured.
Berisha has been seeking to return to power, tapping not only outrage over Hajdari's killing but also widespread disappointment with the government's inabiliy to revive the economy.