THAILAND'S prime minister invoked a special security law in Bangkok and nearby areas after protesters occupied the foreign and finance ministries calling for her resignation.
The demonstrations against Prime Minister Yingluck Shinawatra are the biggest since 2010, when the Thai capital was engulfed in weeks of deadly violence between the red shirt supporters of the Pheu Thai party, and the yellow shirts who back the opposition Democrat Party.
An estimated 1,000 protesters broke into the finance ministry in the early afternoon, taking over seven floors of the building and forcing the staff to evacuate to the car park.
Another group entered the compound of the foreign ministry, but said they would not occupy the building itself.
The law authorises officials to seal off roads, take action against security threats, impose curfews and ban the use of electronic devices in designated areas.
Tensions between the rival political groups have been mounting after a failed attempt earlier this month by Pheu Thai to push a controversial amnesty bill through parliament.
Critics said the legislation would have allowed the return from exile of former prime minister Thaksin Shinawatra, Ms Yingluck's brother.
Pheu Thai's opponents regard Ms Yingluck as a proxy for Mr Thaksin, who was overthrown in a 2006 military coup and fled Thailand two years later to avoid corruption charges. Many believe he continues to run the country from his base in Dubai.
"Our only objective is to overthrow the Thaksin regime," said Suthep Thaugsuban, the leader of the protesters and a former Democrat Party MP. Mr Suthep called on the demonstrators to occupy all government offices today.
The US said it was concerned about the rising political tensions and was monitoring the situation closely.
"We urge all sides to refrain from violence, exercise restraint, and respect the rule of law," said Jen Psaki, state department spokesman. So far, the protests have been peaceful and the Thai army has stayed in its barracks.
Yet with around 40,000 red shirts gathered in a sports stadium on the outskirts of Bangkok, there are growing fears of a repeat of the violence of 2010, when 90 people died and thousands were injured.
Yesterday, however, Ms Yingluck dismissed the calls for her to step down. "I have no intention of resigning or dissolving parliament," she said.
A no-confidence debate in Ms Yingluck and the Pheu Thai government begins tomorrow. (© Daily Telegraph, London)