BANGKOK (Agencies) - Thousands of Thai anti-government protesters flouted a state of emergency in Bangkok on Sunday, rallying against embattled Prime Minister Abhisit Vejjajiva after he ordered tanks onto the streets. Tanks and armoured vehicles rumbled across the Thai capital as Thai Premier Abhisit Vejjajiva cracked down on protesters leading the most serious challenge yet to his four-month rule. Dozens of demonstrators fired into the air, attacked Abhisits convoy, captured armoured vehicles and roamed the streets of the capital - a day after forcing the cancellation of a summit of Asian leaders in a major humiliation for the government. They also stormed the countrys Interior Ministry and pelted Abhisits car with rocks, chairs, flags and sticks as he escaped. Abhisit said he was safe and unhurt after the incident, and called for calm while threatening the use of force to restore order. Col Sunsern Kaewkumnerd told AFP the army, navy and air force had been deployed to ensure the security of public buildings, junctions and transport hubs at 50 spots in Bangkok. Military and police reinforcements were also seen arriving to protect the Royal Palace compound. The red-shirted supporters of fugitive former prime minister Thaksin Shinawatra massed outside Abhisits offices as night fell Sunday despite the premiers threats to use force to restore order. Thaksin called for a revolution after rioting erupted in the capital, with protesters commandeering public buses and swarming triumphantly over military vehicles in unchecked defiance. You dont have to be frightened of this state of emergency. I was the one who drafted the law, Thaksin said in one of two telephone speeches to around 15,000 red-shirted loyalists. This is a golden minute. We will make history, added Thaksin. A military-run network and CNN affiliate MCOT earlier quoted Thaksin as urging his supporters to revolt. He also said he would return from exile if there was any violence. Its total chaos. It is scary and the military are doing nothing. Who can guarantee our safety? said Martin Liu, a 36-year-old American tourist near the armoured vehicles. The latest escalation in Thailands chronic turmoil came after police arrested the leader of the activists who forced the cancellation of Saturdays Asian summit in Pattaya, sparking renewed tensions with demonstrators. Troops fanned out across the city to curb the most serious civil unrest of Abhisits four-month rule, while armoured vehicles stood guard outside key government installations. Protesters waving red flags stood atop one armoured car as it sped along a highway with a soldier at the wheel, amid reports that the demonstrators had captured at least one of the vehicles. Television pictures showed red-shirted protesters armed with sticks and paving slabs smashing a car they mistakenly believed was carrying the prime minister as it left the Interior Ministry minutes after he issued the emergency decree. British-born Abhisit later warned of tough action after two weeks in which security forces have repeatedly failed to take on protesters, both in Bangkok and at the Pattaya summit. I want to tell protesters that you have no right to break the law or to restrict other peoples rights. Otherwise the government must implement further measures under the state of emergency, Abhisit said, alluding to using force. Abhisits deputy Suthep Thaugsuban also appeared on national television to appeal to soldiers and police to enforce the emergency measures, amid signs they were reluctant to intervene. The move bans public gatherings of more than five people and empowers the police and military to detain suspects for up to 30 days without charge.