As political crisis deepens in Albania, the government and opposition have traded blame over who is responsible for the deaths of three protesters during an earlier anti-government demonstration.
The prosecutor general's office said on Saturday that arrest warrants have been issued for six officers of the National Guard, a force of army troops under the command of the interior ministry tasked with guarding government institutions and senior officials.
Tensions have been mounting for months between the government and the opposition, led by the Socialist Party.
The opposition vowed to hold further protests after the three people were killed in Friday's violent demonstration against Sali Berisha, the country's prime minister. Berisha has called demonstrations of his own against what he terms as "the violence of the opposition."
Two of the men were shot in the chest, while one died of a head wound in the demonstrations on Friday, where protesters threw sticks and stones at Berisha's office building, prompting police to retaliate with tear gas, rubber bullets and water cannons.
Berisha said the men had been killed by "bandits" within the ranks of the protesters themselves, and he accused Edi Rama, the leader of the Socialist Party, of attempting a coup.
He warned that those who organised the "anti-constitutional putsch ... will have to face the consequences of law".
He said that the demonstrators included "gangs of criminals, bandits, traffickers and terrorists".
Rama accused Berisha of being the "political orchestrator" of the deaths, and called for the arrest of Lulzim Basha, the interior minister.
"We will continue our protests and demonstrations, without violence, peacefully, wisely, with the unstoppable power of the people's resistance," he said after the first funeral for a protester on Saturday.
In addition to fuelling outrage over corruption allegations, the opposition has also alleged that Berisha's Democratic Party rigged Albania's 2009 elections.
Calls for calm
Alexander Arvizu, the US ambassador to Albania, called for calm, saying that violence was neither necessary nor "inevitable".
"What Albania desperately needs at this moment is political leadership. We have repeatedly urged Albania's political leaders to search for compromise," he said.
Arvizu, together with Ettore Sequi, the EU ambassador, and Fiona McIlwham, the British ambassador, met with Bamir Topi, the Albanian president, to stress that the "return of dialogue, respect of institutions, maturity and equilibrium is of a vital importance".
Eugen Wollfarth, ambassador for the Organisation for Security and Co-operation in Europe (OSCE), called "all national leaders, both in government and in opposition" to act "constructively and show leadership in restoring public and political confidence so that the country again can focus on its national strategic goals".
Friday's protest, which attracted more than 20,000 people, was prompted by the resignation of Ilir Meta, the country's deputy prime minister, after a video surfaced allegedly showing him asking a colleague to influence the awarding of a contract for building a power station.
'Very tense' situation
Speaking to Al Jazeera from Tirana, Besar Likmeta, editor of the website BalkanInsight.com, said: "The political situation continues to be very tense here and the opposition and the government are accusing each other of murder.
"The general prosecutor's office has initiated an investigation into the deaths and issued warrants for six high-ranking officers of the National Guard. But unfortunately the police aren't enforcing these warrants."
Meanwhile, Amnesty International (AI), the UK-based human-rights group, has urged Albanian authorities to investigate the deaths that resulted from the Tirana protests.
Andrea Huber, AI's deputy director for Europe and Central Asia, said: "The police have a right to maintain order and protect the public, but they must not use excessive force against those carrying out their legitimate right to protest."
Friday's demonstrations marked the first time opposition protests had ended in violence since a political crisis erupted in Tirana after the disputed 2009 general elections.
Elections in the country have often been marred by violence and allegations of fraud since the collapse of Albania's communist government in 1991. The current impasse is the longest political crisis the country has faced.