Thai protesters have surrounded several more government ministries, amid anti-government demonstrations in Bangkok.
The protesters want PM Yingluck Shinawatra's government to resign, saying it is controlled by her brother - ousted former PM Thaksin Shinawatra.
After a huge rally on Sunday, they marched to several Bangkok locations.
Ms Yingluck has invoked special powers allowing officials to impose curfews, but said on Tuesday that authorities would "absolutely not use violence".
"Everybody must obey the law and not use mob rule," she told reporters.
"If we can talk, I believe the country will return to normal," Ms Yingluck added.
She invoked the Internal Security Act late on Monday.
Thailand's criminal court has issued an arrest warrant for former opposition Democratic Party lawmaker Suthep Thaugsuban, who has been leading protests triggered by a controversial political amnesty bill.
The demonstrators say the legislation - which failed in the Senate - would have allowed Mr Thaksin to return to Thailand without serving the jail sentence he was given in 2008 after being convicted in absentia of corruption.
Thailand has been bitterly divided since Mr Thaksin was ousted in a military coup in 2006, and the proposal re-ignited simmering political tensions.
Groups of protesters camped out at the foreign and finance ministries overnight. On Tuesday, they surrounded the interior, tourism, transport and agriculture ministries.
About 1,000 protesters gathered outside both the finance and interior ministries, blowing whistles and chanting "get out!", reports said.
Akanat Promphan, a protest spokesman, said: "We are occupying the finance ministry in a non-violent and peaceful way, so our supporters around the country can do the same and occupy all government offices."
However Thida Thavornseth, a leader of the "red shirts", who support Mr Thaksin, told AFP news agency that Mr Suthep "wants to throw out democracy and replace it with an ultra-royalist administration".
The opposition Democrat Party has also started a censure motion in parliament against the government, over its alleged misuse of the budget.
The motion highlights an expensive rice subsidy scheme launched by the government after it took office.
Under the scheme, the government bought rice directly from farmers, paying more than the market rate. India and Vietnam increased their share of global rice exports as a result, overtaking Thailand as the world's largest rice exporter.
The government is expected to defeat the censure motion, since the ruling Pheu Thai party has a majority in parliament.
But, with a timid and poorly-trained police force, it is not clear how the government can reassert its authority in a city where a sizeable part of the population say they have lost all faith in their democracy, says the BBC's Jonathan Head in Bangkok.
The protests are the biggest to hit Thailand since the violence of 2010, when "red-shirt" opponents of the then Democratic Party government occupied key parts of the capital.
More than 90 people, mostly civilian protesters, died over the course of the two-month sit-in.
A government led by Ms Yingluck and the ruling Pheu Thai Party was subsequently elected and since then Thailand has remained relatively politically stable.
But the opposition accuse Mr Thaksin of running the government from self-imposed exile overseas, and the now-shelved amnesty bill has served as a spark for renewed protests.
Speaking in parliament on Tuesday, she said: "There are some accusations that I lack independence, and that I lack intelligence, and have to be controlled by pushing a button.
"I have to say, have I not been independent in the past two years that I administered the country as the head of the government?"