A spoof television report that President Mikheil Saakashvili had been assassinated in a new Russian invasion of Georgia led to mass panic and furious opposition protests yesterday.

The 30-minute programme claimed that Russian forces were advancing on the capital Tbilisi and had bombed its airport, and that opposition leaders had sided with the Kremlin.

The primetime broadcast on the private Imedi TV channel carried only a brief notice that it was a “simulation” of possible events following Georgia’s war with Russia in 2008.

The emergency services were deluged with callers who believed the broadcast was genuine. Some viewers reportedly suffered heart attacks as they watched footage of Russian tanks entering Georgia and people began to flee the northern city of Gori, which was occupied during the last war.

The station broadcast fake clips of President Medvedev telling security chiefs to “neutralise” Mr Saakashvili and of President Obama urging Russia to halt military action.

It said that Nino Burjanadze and Zurab Nogaideli, two opposition leaders who have met Vladimir Putin, the Russian Prime Minister, in Moscow recently, had backed Russia and encouraged Georgian troops to mutiny.

Mrs Burjanadze, a former ally of Mr Saakashvili who has turned against him, accused the Government of inspiring the programme to smear the opposition. Imedi is run by a former minister and close ally of the pro-Western President.

“This Government’s treatment of its own people is outrageous. I am sure that every second of this programme was agreed with Saakashvili,” she said.

“Every word about me was malicious slander and I will sue both Imedi television and the authorities.”

Eka Tkeshelashvili, the head of Georgia’s National Security Council, denied that the Government had had advance knowledge of the broadcast, saying: “This programme was an extremely unpleasant surprise to the authorities.”

Mr Saakashvili appeared to defend its contents, however, telling Georgian television: “It was indeed a very unpleasant programme but the most important thing is that it is extremely close to what can happen and to what Georgia’s enemy has conceived.”

In remarks aimed at Mrs Burjanadze, he added: “Those who are shaking hands with people who have Georgian blood on their hands will never be respected.”

The channel apologised after Saturday’s broadcast, saying that it should have been clearer that the events were not real. But it defended the programme as a means of “obstructing Russia’s aggressive plans” towards Georgia.

Russian tanks came within 20 miles (32km) of Tbilisi and troops occupied large swaths of Georgia during the war over South Ossetia.

Mr Medvedev has stationed thousands of combat troops in South Ossetia and nearby Abkhazia, which he has recognised as independent states but which legally are still part of Georgia.

Russia’s ambassador to Nato, Dmitry Rogozin, accused Mr Saakashvili of spreading “lies and shocking provocations” through the programme. “This is a sick and dangerous man and his actions are criminal,” he added.