BANGKOK — Thai Prime Minister Yingluck Shinawatra fought a two-front political war yesterday, fending off attacks during a parliamentary no-confidence debate, while protesters besieged and occupied several ministries, vowing to take control of state offices nationwide in a bid to oust her.

Escalating the biggest challenge Ms Yingluck has faced since taking office, protest leaders threatened to extend the battlefield to government offices in provincial areas, while the police issued an arrest warrant for protest leader Suthep Thaugsuban, a former opposition lawmaker who led the storming of the Finance Ministry a day earlier. But the police said he would not be arrested at the rally as part of a pledge to avoid clashes with protesters.

Civil servants yesterday fled as groups of demonstrators surrounded the interior, agriculture, tourism and transport ministries in blockades that have plunged Thailand into its deepest political uncertainty since it was convulsed by the bloodiest unrest in a generation in 2010. Protesters cut electricity and water at the Interior Ministry to pressure people inside to leave.

Protesters say they want Ms Yingluck, who took office in 2011, to step down amid claims that her government is controlled by her brother, former Prime Minister Thaksin Shinawatra, who was ousted in a military coup in 2006.

Mr Thaksin has lived in self-imposed exile for the past five years to avoid a two-year prison sentence on a corruption conviction.

Yesterday, the main protest group appeared to have converted the Finance Ministry, where they camped overnight, into its headquarters, and declared Tuesday a “rest day”, as protesters erected tents in the parking lot.

“Tomorrow (Wednesday), there will be a nationwide movement,” Mr Akanat Promphan, a spokesman for the protests, said yesterday. He said the aim is to paralyse government operations by seizing offices and state agencies so they cannot be “used as a mechanism for the Thaksin regime’’.

The opposition Democrat Party is spearheading the demonstrations. Together with former Democrat Prime Minister Abhisit Vejjajiva, protest leader Suthep has previously been charged with murder for allowing troops to open fire in the 2010 protests by Thaksin’s supporters. An unexploded hand grenade was found outside a Democrat Party office in Bangkok yesterday, the police said.

Separately, the Democrat Party launched a parliamentary no-confidence debate yesterday against Ms Yingluck. The vote has no chance of unseating her as her ruling Pheu Thai Party controls the House of Representatives.

Ms Yingluck called for calm and offered to negotiate with protest leaders. “If we can talk, I believe the country will return to normal,” she said.

The Prime Minister has vowed not to use violence to stop the protests but expanded special security laws late on Monday to cover the entire capital. The Internal Security Act was already in place for three districts of Bangkok since August, when there were early signs of political unrest. It authorises officials to impose curfews, seal off roads, restrict access to buildings and ban the use of electronic devices in designated areas.

On Sunday, more than 100,000 demonstrators took to the streets of Bangkok’s, uniting against what they call the “Thaksin regime”.

What started a month ago as a campaign against a political amnesty Bill has morphed into a wider anti-government movement. Protest leaders now say their ultimate goal is to uproot the Shinawatra network from Thai politics, with no explanation of what that means.

“Every time you think that Thailand is moving along, the government’s ability to govern breaks down. We have gone through this many times since 2006,” said JP Morgan analyst Matt Hildebrandt.

Protesters’ takeover of government offices has drawn criticism from the United States and the European Union. The latter issued a statement yesterday, calling upon “all concerned to avoid escalation and to resolve differences through peaceful means”.

Singapore, China and the United Kingdom have also expressed concern.

The Ministry of Foreign Affairs (MFA) has advised Singaporeans travelling to Bangkok to stay away from large crowds and demonstrations, monitor local news and developments closely, take all necessary precautions for personal safety and buy comprehensive travel and medical insurance.

Singaporeans are encouraged to register with the MFA at http://eregister.mfa.gov.sg so the ministry can contact them should the need arise. Singaporeans who are in need of consular assistance while in Bangkok may contact the embassy there at 001-66-(2) 286-2111 or 001-66-(81) 844-3580. AGENCIES