At least 10 die and 500 injured in Thai riots

Troops and protesters traded petrol bombs and rubber bullets during running skirmishes in Bangkok

The streets of Bangkok resembled a war zone yesterday as government troops fired rubber bullets and tear gas at thousands of demonstrators who responded by hurling petrol bombs in the most serious clashes yet of a month-long protest.

At least 15 were killed and more than 650 – many of them police – were injured in running skirmishes in the Thai capital, as crowds of so-called Red Shirts, the supporters of the former prime minister Thaksin Shinawatra, pressed their demands for fresh elections and an immediate dissolution of parliament. In some instances, security forces fired live rounds near the heads of the demonstrators in an effort to enforce the state of emergency declared earlier in the week. They also used water cannons.

The military vowed to clear one of the protesters' main encampments by nightfall, but did not. By early evening, a pitched battle was under way near the protesters' camp. The Thai media reported both sides firing guns, and the use of small bombs. Details were difficult to confirm, but videos showed chaotic scenes of fighting in streets enveloped in tear gas before the army pulled back after several hours of fighting. Most of yesterday's earlier confrontations involved pushing and shoving by the two sides, though some protesters wielded sticks and threw rocks. But tear gas was used frequently by the soldiers, who, as well as using rubber bullets, also fired M16 assault rifles in the air. A reporter for the Thai TV station TPBS showed a spent bullet and bullet hole in the side of a car. The protesters responded with petrol bombs and grenades.

More troops were also sent to a second rally site in the heart of Bangkok's tourist and shopping area, "to pressure the protesters", the reporter said. The city's elevated mass transit system known as the Skytrain, which runs past that site, stopped operations and closed all its stations as possible confrontation loomed. Merchants say the boisterous demonstrations have cost them the equivalent of millions of dollars, and luxury hotels near the site have been under virtual siege.

Last night, as darkness fell, both sides appeared to be regrouping ahead of what will likely be further clashes today. The security forces appeared particularly concerned about protesters gathering at the Kok Woa intersection, which leads to Bangkok's famous backpacker neighbourhood of Khao San Road. "We fear sabotage by the Red Shirts, so we are reinforcing troops on Rajdamnoen Road and around the area to make sure the situation doesn't spiral out of control," an army spokesman, Sansern Kaewkamnerd, told Reuters.

Yesterday's clashes, which will have caused mounting concern for a government worried about the effect such scenes will have on the country's crucially important tourism industry, come after weeks of protests by anti-government activists. Earlier this week, the country's Prime Minister, Abhisit Vejjajiva, declared emergency rule in the city after scores of protesters broke into the grounds of the parliament, forcing some officials to flee by helicopter. The demonstrators also broke into the compound of a satellite television station that the government had closed down.

Demonstrators, who had prepared for the clashes by carrying wet towels to cover their faces against the tear gas, said last night that they now wanted the parliament dissolved at once. "We are changing our demand from dissolving parliament in 15 days to dissolving it immediately," declared the protest leader, Veera Musikapong. "And we call for Abhisit to leave the country immediately."

The clashes, in which the Red Shirts used taxis and pick-up trucks to build barricades behind which they stood, pitch the supporters of Mr Thaksin, ousted in a 2006 coup, against a government which they believe came to power unconstitutionally. The British-educated Mr Abhisit became premier in late 2008, after a series of legal and constitutional crises saw two previous prime ministers – both allies of Mr Thaksin – forced from office. Their supporters say that, because Mr Abhisit was not directly elected by the public, he has no popular mandate and that it is essential for new elections to be held to "restore democracy" to Thailand.

But the faultlines of the dispute go much deeper. Mr Thaksin, currently in exile after having been found guilty in absentia of corruption and having had more than $1bn of his assets frozen, has drawn much of his support from Thailand's rural areas, where many were impressed by a series of populist policies he introduced during his two terms as prime minister.

At the same time, the Red Shirts say they are seeking to counter the influence of the conservative elements of Thai society – military officers, business owners – who have opposed Mr Thaksin, some of whom helped trigger the bloodless 2006 military coup that took place when the then prime minister was out of the country. Neither the Red Shirts nor the government appear ready to back down.

"I'd say the demonstrators are becoming increasingly desperate to find a way of forcing the government to dissolve parliament. That said, the authorities – especially the deputy Prime Minister, Suthep Thaugsuban – are apparently even more desperate to see the protesters dispersed," said Professor Duncan McCargo, a South-east Asia specialist at Leeds University. "The best way forward would be through some form of negotiation or compromise, but both sides seem intent on sticking with street confrontations. There seem to be no neutral figures left who are able to play honest broker in this increasingly dangerous stand-off."

To confront the protesters effectively, Siripan Nogsuan Sawasdee of Chulalongkorn University said the government needed the co-operation of the military, but it could be that the army is reluctant to use massive force against the protesters.

Yesterday's demonstrations in Bangkok coincided with the first protests outside of the capital. In the northern city of Chiang Mai, the hometown of Mr Thaksin, hundreds of protesters forced their way into the governor's office compound. Protest leaders made fiery speeches on a makeshift stage, calling on the government to dissolve parliament and stop the crackdown. Meanwhile, in the north-eastern town of Udon Thani, hundreds of people broke through the gates into the compound of the town hall.

On Friday, protesters had broken into the Thaicom transmission station and briefly restarted a pro-Red Shirt television station that had been shut down by the government under the state of emergency. After scattered hand-to-hand scuffles, the troops retreated in disarray, some taking positions inside the main Thaicom building. About a dozen people were hurt.