Thai authorities have extended a curfew in Bangkok for three more nights, following Wednesday's army operation against anti-government protesters.
The curfew will also be in place in 23 provinces, officials say.
Bangkok remains tense after its first night under curfew and shots were heard early on Thursday near a temple where many protesters had sought shelter.
Protesters set some 27 buildings ablaze on Wednesday after their leaders had surrendered.
Pockets of resistance still reportedly remain.
Some 40 people have died since troops surrounded the protesters last week, with at least 14 more deaths on Wednesday.
The next curfew will begin at 2100 local time (1400 GMT) on Thursday, army spokesman Dittaporn Sasasmith said.
It will run until 0500 the following day (2200 GMT Thursday) and the times will be repeated for the next two nights.
"This will help security forces provide security for the public and prevent further violence," the spokesman said.
He added that "police and soldiers told the prime minister [Abhisit Vejjajiva] that the curfew last night [Wednesday] went well".
However, the BBC's Chris Hogg in Bangkok says the authorities have admitted some areas of the Thai capital are not yet safe.
Soldiers and police were fired on when they tried to enter a temple where several thousand protesters had taken refuge, he adds. Reports say those inside the building are now leaving.
Reuters news agency quoted a spokesman for Bangkok's governor as saying there were 31 fires on Thursday morning. Banks, department stores and hotels have been targeted.
There are fears that Central World, one of South-East Asia's biggest shopping centres, could collapse after it was set ablaze by the protesters, Thai police officials were quoted as saying by AFP.
The stock exchange suffered a small fire and will be closed on Thursday and Friday. Banks in other parts of the country will also stay shut.
Buses were running in the capital on Thursday morning and TV channels continued to show approved programmes.
Some of the protest leaders are being held at a police camp outside the city, where they are being questioned, while others have escaped, our correspondent says.
Meanwhile, forensics teams are collecting evidence in the now empty protest camp area as armed officers search buildings nearby in a hunt for weapons, he adds.
At least six people died on Wednesday during the army crackdown on the protesters' fortified camp in the Lumpini Park area of central Bangkok.
However, witnesses and police now say that at least eight more people were killed in the temple inside the protesters' site after the army assault.
There were outbursts of violence in some places in the red-shirt stronghold in the north-east, forcing the authorities to also impose an overnight curfew in 21 provinces.
In a televised address late on Wednesday, Mr Abhisit said he was "confident and determined to end the problems and return the country to peace and order once again".
Thaksin Shinawatra, the former prime minister living in self-imposed exile whom many red-shirts support, warned that the crackdown could spawn mass discontent and lead to guerrilla warfare.
'Out of control'
Wednesday's curfew, the first imposed in Bangkok in 15 years, ran from 2000 to 0600 (1300 to 2300 GMT), and the government ordered television channels to broadcast only officially sanctioned programmes.
The protest may be over but the bloodshed will not be forgotten and the bitterness and anger linger on, reports the BBC's Rachel Harvey from Bangkok.
Thailand's deep divisions have been brutally exposed, our correspondent adds.
There are reports of tension in the north and one group operating in the capital declared itself independent of the main protest movement and said it would continue fighting.
In the north-east of the country, a town hall in Udon Thani was set on fire and another, at Khon Kaen, was wrecked. Violence was also reported in the northern city of Chiang Mai.
The US state department said it deplored the violence and urged restraint on both sides.
EU parliamentary president Jerzy Buzek said national reconciliation was now "not simply an option, it is absolutely mandatory".
Among the dead on Wednesday was an Italian photojournalist, while three other reporters, a Dutch person, an American and a Canadian, were among scores of people injured.
The red-shirts had been protesting in Bangkok since 14 March, occupying the shopping district, forcing hotels and shops to close.
But events took a deadly turn last week when the government moved to seal off the area and a renegade general who backed the protests was shot dead.
The red-shirts are a loose coalition of left-wing activists, democracy campaigners and mainly rural supporters of Mr Thaksin.
They are demanding fresh polls because they say the government - which came to power through a parliamentary deal rather than an election - is illegitimate.