Thousands of riot police have been deployed in Bangkok to clear areas occupied for weeks by opposition protesters, tearing down makeshift barricades around the besieged government headquarters.
The operation in the Thai capital on Friday marked an unexpected shift in tactics by Prime Minister Yingluck Shinawatra's government after months during which the demonstrators have often appeared to be more in control of the city than the authorities.
Apparently emboldened by dwindling protester numbers and the failure of the opposition to have a recent election nullified by the courts, the government attempted to regain the upper hand by reclaiming key state buildings.
Police with shields and riot helmets, some carrying rifles, met little resistance as they re-took areas around Government House, which Yingluck had been unable to use for about two months.
Security forces removed protesters' tents and ripped down their makeshift defences built from barbed wire, sandbags and piles of rubber tyres, according to AFP reporters.
But it was unclear if the operation was a success as demonstrators were later seen rebuilding barricades. Police also pulled back from an occupied government complex in the north of the city before they could clear the area.
Thailand remains deeply divided more than seven years after a controversial military coup ousted then-premier Thaksin Shinawatra - Yingluck's brother.
The kingdom has been periodically rocked by mass demonstrations by rival protest groups broadly allied or opposed to the tycoon-turned-politician, who wooed rural voters with policies such as affordable healthcare and micro-loans.
Thaksin is hated by many southerners, middle-class Thais and members of the Bangkok elite who see him as authoritarian, corrupt and a threat to the revered monarchy.
The deployment of security forces revived memories of a bloody crackdown on mass pro-Thaksin "Red Shirt" rallies in 2010 under the previous government, using armed troops backed by armoured vehicles.
Unlike on that occasion, when scores were killed, there were no serious injuries in Friday's operation, which targeted an area of the government district where few demonstrators remained, rather than the main rally stages in the heart of the commercial district.
So far the authorities have not announced any plan to clear major intersections in the retail and hotel districts that have become the main focus of the rallies in recent weeks as part of what protesters have described as the "Bangkok shutdown".
National Security Council chief Paradorn Pattanatabut said the authorities planned to re-take several other government buildings including the interior ministry, and arrest protest leaders.
He described the operation as "successful", pointing to the weapons seizure.
"Although protesters came back they are not intruding into Government House," he said.
But a spokesman for the anti-government movement, Akanat Promphan, criticised the operation as a "total failure".
"We will continue to demonstrate until we win," he added. "We will resist any attempt to reclaim rally sites using non-violence."
The demonstrators want Yingluck to stand down to make way for an unelected "People's Council" to enact reforms to tackle corruption and alleged vote-buying before new polls are held.
