BANGKOK // Buildings smouldered across central Bangkok early today and troops exchanged sporadic fire with pockets of holdouts a day after the army routed anti-government protesters in a push to end Thailand's deadliest political violence in nearly 20 years. Although the government quelled most of the violence in the battered Thai capital, it announced that a night time curfew had been extended in Bangkok and 23 other provinces for three more days. A major military operation the day before, in which at least seven people were killed and 88 wounded, was largely successful, but underlying political divisions that caused Thailand's crisis may have been exacerbated, and unrest spread to provinces in the north and north-east. Bangkok's skyline overnight was blotted by flashes of fire and black smoke from more than three dozen buildings set ablaze - including Thailand's stock exchange, main power company, banks, a cinema and one of Asia's largest shopping malls. The government described the mayhem as "an organised crime. It is terrorism". An army spokesman Col Sansern Kawekamnerd said authorities found a cache of explosives and assault rifles during their sweep against the Red Shirts. Troops in the central business district, occupied by protesters for weeks, exchanged occasional fire this morning with hold-outs as locals in the area looted a vast tent city the activists had cobbled together. Since the Red Shirts began their protest in mid-March, at least 75 people, mostly civilians, have been killed and nearly 1,800 wounded. Of those, 46 people have died in clashes that started May 13 after the army tried to blockade their camp, which measured three square kilometres. Elsewhere in the city, municipal workers removed debris and collected piles of rubbish left in the streets that had been cordoned off by authorities for the past week. Col Sansern said there had been a total of 39 arson attacks, which officials said included office buildings, banks, gold shops, a hotel, government offices and convenience stores. While many of the rioters were believed to be members of the Red Shirts and their sympathisers, there also was an element of criminals and young hoodlums involved in the mayhem in the city of 10 million people. The violence in one of South East Asia's most stable countries has damaged its economy and tourism industry. With the top Red Shirt leaders in custody, it was unclear what the next move would be for the protesters who had demanded the ouster of the prime minister Abhisit Vejjajiva's government, the dissolution of parliament and new elections. The protesters, many of them poor farmers or members of the urban underclass, said Mr Abhisit came to power illegitimately and is oblivious to their plight. Many Thais feel that any short-term peace may have been purchased at the price of further polarisation that will lead to years of bitter, cyclical conflict. "The Reds rampaged and committed to armed resistance," said Thitinan Pongsudhirak, a political scientist from Bangkok's Chulalongkorn University. "Right now, they are just burning buildings, but later on, what if they picked up arms to fight the bureaucrats, security forces in other parts of Bangkok, and especially in the countryside? So this is just the beginning. The crackdown didn't make them retreat fully. Things will get much worse still." Mr Thitinan said the government will need to seek a political settlement. "The problem now is that who does the government talk to?" he said. Some point to the former prime minister Thaksin Shinawatra, who was ousted in a 2006 military coup and fled into exile before being sentenced to two years in prison for corruption. The government has accused him of bankrolling the protests and refuses to make any deals with him until he comes back to serve his sentence. * AP