Thai prime minister invokes security law as protesters storm ministries in Bangkok (VIDEO)

Thailand's embattled prime minister said Monday that the government would invoke a special security law in the capital and surrounding areas after a series of anti-government protests.

Protesters, led by the opposition Democrat Party, stormed the Finance Ministry and Foreign Ministry in a bid to topple Prime Minister Yingluck Shinawatra. Elsewhere in Bangkok, as many as 30,000 demonstrators marched on state agencies including military and police bases.

Under the Internal Security Act that Yingluck invoked Monday, officials would be able to impose curfews and block roads.

Demonstrators reportedly broke down the gates to the Foreign Ministry and asked civil servants to leave without returning to work the next day, according to a ministry spokesman.

GlobalPost's Patrick Winn took a look:

"It was a peaceful seizure by the people," protest leader Suthep Thaugsuban said at a press conference. "The Thaksin system can no longer work," he said, referring to the self-exiled former leader who is the current prime minister's brother.

Thaksin was ousted in a military coup in 2006, and found guilty of graft two years later — charges he denies.

The latest protests come just a day after more than 100,000 protested in Bangkok's historic quarter.

The prime minister said the protests "threaten the stability of the government."

Opposition protesters accuse Yingluck of being her brother Thaksin's puppet. Anti-government sentiment has been brewing since last month when an amnesty bill backed by the government could have allowed Thaksin to return to politics. The bill did not pass parliament, but it was enough to trigger rallies against Yingluck.

"I have no intention to resign or dissolve the House," Yingluck said.

Yingluck rose to power in 2011, chiefly thanks to the support of the Red Shirts — supporters of Thaksin.

Thailand is no stranger to political instability, as protests in 2010 left more than 90 civilians dead. The Southeast Asian country has seen 18 attempted or actual coups since becoming a constitutional monarchy in 1932.

The United States called for calm Monday, concerned about the political tensions in Thailand.

"We urge all sides to refrain from violence, exercise restraint, and respect the rule of law. Violence and the seizure of public or private property are not acceptable means of resolving political differences," said State Department spokeswoman Jen Psaki in a statement.

The Associated Press released this raw footage of clashes between protesters and riot police: