* Fake report: Russian tanks invade at call of opposition
* After 2008 war, stunt sparks panic in Georgia
TBILISI, March 14 (Reuters) - Georgia's opposition accused the government on Sunday of being behind a fake primetime news report that Russian tanks had entered the capital at the call of the opposition, causing widespread panic.
For many Saturday night viewers, the 20-minute report on pro-government Imedi TV thrust the country back to its five-day war with Russia in August 2008.
The report laid out a scenario in which opposition leaders called on Russian forces now stationed in South Ossetia to intervene in political unrest following mayoral elections in Tbilisi, which are due by the end of May.
Imedi, which is run by a close ally of President Mikheil Saakashvili, did not hide the fact the report was in response to two opposition leaders meeting separately with Russian Prime Minister Vladimir Putin late last year and this month.
The aim, it said, was to demonstrate how events might unfold.
The opposition was furious, saying the stunt raised fresh questions over what international watchdogs say is state manipulation of news media under Saakashvili.
Government officials have denied involvement. Asked if Saakashvili was involved or aware of the report before it aired, his spokeswoman said she was unable to comment.
"Full responsibility for the preparation and the results of the report lie with the Georgian authorities, which have practically monopolised all television space in order to wage information terror on their own people," the opposition Alliance for Georgia said in a statement.
Introduced as a simulation of "the worst day in Georgian history", the report then ran without a banner making clear it was not real. Mobile phone networks crashed and the emergency services reported a spike in calls.
Many Georgians rushed home, and some Russian media interrupted their regular programming.
Imedi, originally an opposition broadcaster until police stormed the studios in 2007 at the height of protests against Saakashvili, apologised for how the report was presented.
Saakashvili also criticised the panic it caused, but said the scenario was not unlikely.
"It was really an unpleasant film, but more unpleasant is that fact the report was maximally close to what could happen or what the enemy of Georgia has in mind," local news agencies reported him as saying on Sunday.
The report underlined the stir caused by opposition politicians Zurab Nogaideli and Nino Burjanadze by meeting Putin and calling for ties between the countries to be restored.
Russia crushed an assault by U.S. ally Georgia on the rebel region of South Ossetia in 2008, sending tanks to within 45 km (28 miles) of Tbilisi.
"Whoever shakes the hand covered in the blood of Georgians of all ethnicities has no dignity," Saakashvili was quoted as saying. (Additional reporting by Margarita Antidze; Editing by Charles Dick)
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