TBILISI - The EU and Georgia's influential Orthodox Church leader urged political forces in the former Soviet republic to step back from the brink on Thursday after weeks of protests against the president flared into violence.

Riot police wielding batons fought stick-wielding protesters on Wednesday night in Tbilisi and 28 people were injured. The previous day, a brief rebellion by a tank battalion cast a shadow over the start of month-long NATO exercises in Georgia that have angered neighboring Russia.

The head of Georgia's influential Orthodox Church, Patriarch Ilia II, warned overnight the situation was in danger of exploding and urged the opposition not to step outside the law.

Czech ambassador Ivan Jestrab, representing the rotating EU presidency, told reporters that Georgia's government and opposition should start talks on the political solution of the existing situation.

Tensions are running high in the volatile South Caucasus country, which fought a five-day war with Russia last August when Moscow crushed a Georgian assault on the breakaway pro-Russian region of South Ossetia.

The opposition has been protesting and blocking streets in the capital since April 9, demanding President Mikheil Saakashvili resign over his record on democracy and last year's disastrous war. Some opposition leaders said they were ready to meet the president and discuss an end to the stalemate.

If we want to take this country out of the political crisis, he has to discuss with us how, opposition leader Salome Zurabishvili said after meeting foreign diplomats. Around 3,000 people protested outside parliament.

An EU-brokered security meeting planned for Thursday between Georgian, Russian and South Ossetian officials on their front line -- the second such encounter -- was canceled in a dispute over the venue.

Russia blamed Georgia, while Tbilisi said it was South Ossetia which had boycotted the meeting. EU ceasefire monitors said they hoped the talks would be held in the near future.

Wednesday's violence erupted when protesters converged on a police base where three activists were being held over the beating of a journalist working for the state broadcaster. Police and demonstrators clashed with sticks and batons across a metal gate dividing them.

The opposition accused police of firing rubber bullets, which the authorities denied. Twenty-two protesters and six police officers were wounded.

Czech ambassador Jestrab said protesters had attacked police in a criminal act, absolutely intolerable in a democratic society.

FEARS OF WIDER UNREST

The violence stoked fears of wider anti-government unrest following a brief, bloodless mutiny at a tank base near Tbilisi on Tuesday when authorities said battalion commanders had refused orders and were plotting a wider rebellion.

The Georgian government accused Moscow of being behind a coup plot but Moscow dismissed that charge, saying Saakashvili was trying to blame an external foe for his domestic problems.

Responding to a request by the Patriarch, police released the three detained activists, who later said they had been beaten in custody. Television on Tuesday had broadcast pictures of the men slapping and hitting the journalist with a flag pole.

Bearded priests tried to calm the protesters and masked riot police, who hurled insults at each other through a dividing fence on Wednesday night. Television footage showed blood streaming from the heads of several protesters.

Saakashvili came to power of the 2003 Rose Revolution on a promise to consolidate Georgian democracy, a promise his domestic opponents say he has betrayed. He sent in police firing tear gas and rubber bullets to disperse the last anti-Saakashvili demonstrations in November 2007.

Russian Foreign Minister Sergei Lavrov accused Tbilisi of yet another provocation with its allegations of Russian-inspired coup plots.

I am absolutely certain it was not accidental that this provocation was conceived ahead of the NATO exercise in Georgia on May 6, disregarding all our warnings, Lavrov said in comments published by the Interfax news agency

Russia strongly opposes NATO's decision to hold month-long military exercises in Georgia, saying the war games amount to muscle-flexing by the Western military alliance in an area it considers part of its traditional sphere of influence.

Russia