Thailand's humiliated government arrested the leader of protesters who shut down a 16-nation Asian summit, and the prime minister vowed further crackdowns as the demonstrators regrouped in the capital for renewed rallies Sunday.

Arisman Pongruengrong, who spearheaded Saturday's demonstrations, was taken into custody and detained at the headquarters of Thailand's Border Patrol Police on Bangkok's outskirts, police Maj. Gen. Supon Pansua said.

Prime Minister Abhisit Vejjajiva earlier Sunday vowed swift legal action against the protesters who stormed the venue of an East Asian Summit in the beach resort of Pattaya. Abhisit spoke on national television as fears mounted that the country could face violence or a military crackdown in coming days.

Jakrapob Penkair, another protest leader, said members of the United Front for Democracy Against Dictatorship were gathering around Government House, the prime minister's office, which has been the prime focus of their earlier demonstrations demanding Abhisit's resignation.

Several hundred of the red-shirted protesters also rallied outside the downtown headquarters of the Royal Thai Police and at the Criminal Court, where they believe Arisman would be taken after interrogation.

The demonstrators say Abhisit's four-month-old government took power illegitimately and want fresh elections. They also accuse the country's elite — the military, judiciary and other unelected officials — of undermining democracy by interfering in politics.

A tense-looking Abhisit said in a Sunday broadcast that one arrest warrant had already been issued and others would follow in efforts to stem a rising tide of anti-government protests that climaxed in Saturday's melee.

"The police are gathering evidence and preparing to obtain more arrest warrants from the court for those involved in the incident yesterday. Police said they have the evidence," said a government spokesman, Panithan Wattanayakorn.

Thai authorities had to evacuate Asian leaders by helicopter Saturday after hundreds of anti-government protesters stormed into their summit site, forcing Abhisit to cancel the meeting.

"The next three to four days will be crucial for the government to prove itself in restoring peace and order in the country," Abhisit said on television. "The government will take action against those who were involved in the incident yesterday without bias."

Editorials in Bangkok newspapers Sunday lashed out at both the protesters for destroying Thailand's international reputation and the government for a massive security breakdown.

Tourism Council of Thailand Chairman Kongkrit Hiranyakit predicted that the country would lose at least 200 billion baht ($5.6 billion) as foreign tourists shunned the country.

"Some tourists want out quickly for fear that protesters may go on to block the airport like last year. Incoming tourists are questioning security and canceling bookings," he said.

More than 1,000 demonstrators broke through a wall of unarmed soldiers, smashed through the convention center's glass doors and ran through the building Saturday, blowing horns, waving Thai flags and shouting demands for Abhisit to resign.

They declared victory after Abhisit canceled the summit, where leaders of regional powers China, Japan and India, and the U.N. secretary-general and president of the World Bank, planned to discuss the global financial crisis.

"We have won. We have stopped them from holding a summit," Jakrapob Penkair, a protest leader, said in Bangkok. "But we have not achieved our goal yet. We will continue to protest in Bangkok until Abhisit resigns."

Abhisit later denounced the protesters on national television as the "enemies of Thailand."

The country's political tension has simmered since former Prime Minister Thaksin Shinawatra was removed by a military coup in 2006. Thaksin opponents marched last year to remove Thaksin's allies from power, even shutting down the country's main international airport for about a week in November. After a court ordered the removal of the previous pro-Thaksin government, Abhisit was appointed by Parliament in December — sparking Thaksin supporters to take to the streets.

Their numbers grew to 100,000 in Bangkok last week.

Abhisit imposed a state of emergency after the summit was overrun, but revoked it six hours later after regional leaders were safely airlifted to a nearby military airport.

The ongoing protests could prompt the military to intervene — a high possibility in a country that has experienced 18 military coups since the 1930s.

"The situation has gotten completely out of hand. Violence and bloodshed is very much possible" if Abhisit does not resign or dissolve Parliament, said Charnvit Kasetsiri, a historian and former rector of Bangkok's Thammasat University. "If the government cannot control the situation, military intervention is not out of the question."