Police said Sunday they detained three people suspected of conspiring to murder a top opposition leader at an anti-government protest, as the opposition said it would not back down from its campaign against the ruling party for alleged corruption.

The three people detained were planning an attack during a Friday protest march called by Socialist Party leader Edi Rama to honor three supporters killed during a massive demonstration earlier this month, police said.

One of the suspects threatened Rama after his vehicle was damaged during the chaotic Jan. 21 rally, police said in a statement. A Tirana court ruled Sunday that the men could be kept in detention for a month pending further investigation.

The opposition said Sunday it would resume anti-government protests in Tirana and then continue in other cities, although no dates have been set. Rama insists on the resignation of Prime Minister Sali Berisha's government and claims that the conservatives rigged the 2009 vote.

Berisha has refused to resign and has accused the opposition of trying to stage a coup.

Rama repeated his call to the international community to intervene to stop what it called the government's attacks on independent institutions. The opposition is angry over a request by a parliamentary committee formed by the governing Democrats to see telephone records of opposition lawmakers, the country's president, its prosecutor general and the head of the secret police as part of an investigation of the deadly clashes.

"With every day it becomes more difficult to keep up stability in this country," Rama said at a news conference after a meeting of the opposition coalition.

"We are ready for dialogue and compromise but we shall never accept the status quo of this regime," he said.

Tensions rose sharply earlier this month when the country's deputy prime minister Ilir Meta resigned amid allegations he tried to influence a state tender for a hydropower station. The opposition wants Berisha to hold early general elections.

Three opposition supporters were shot dead and more than 150 protesters and security officers were injured in the Jan. 21 clashes between demonstrators and police.

The European Union and the United States have urged restraint from the Socialists and the governing Democrats, who agreed to cancel a protest of their own scheduled for Saturday, calling on them to consider dialogue to manage political differences.