Infantry Assault Routs Protesters in Bangkok : Thailand: Prime minister, whose ouster is demanded, defends use of force. Hundreds arrested in street battles.

Army troops quelled anti-government rioting early today with an infantry assault on a besieged downtown hotel. The attack came after street fighting had raged most of Monday and after the arrest of Thailand’s pro-democracy leader.

At least 19 persons were believed killed in the second day of violence, with scores wounded and hundreds of demonstrators arrested. Some Thai newspapers reported that up to 100 persons may have been killed in the final attack.

Prime Minister Suchinda Kraprayoon, who has been the target of protests since his appointment last month, went on national television and blamed the pro-democracy demonstrators for instigating violence “to achieve their political aims.”

Suchinda said the government had “no other choice than to use military force” to halt the violence and promised to return the nation of 55 million people to peace as soon as possible.

In what may be a precursor of the economic consequences of the unrest, the Thai stock market opened today for the first time since Friday and plummeted 62 points, or about 8%, in the opening two hours.

The bloodiest fighting swirled around the capital’s Royal Hotel, where many demonstrators had taken refuge to avoid the withering police and army fire. Doctors set up a makeshift emergency room in the lobby, and protesters were crammed 30 to a room.

Fighting flared when angry protesters commandeered city buses and tried to crash through police lines. Troops cordoning off the area opened fire with machine guns on the buses, which were packed with young protesters.

Demonstrators set fire to a number of major government buildings that surround the Royal Hotel, including the government public relations office, a lottery bureau and the tax department. The buildings were gutted and still burning out of control hours later.

The army then chased the demonstrators through the narrow streets, firing directly into the crowds in an effort to disperse them. The streets were littered with what appeared to be dead and seriously wounded people. The death toll appeared certain to rise sharply.

These tough measures provoked an angry response from a growing crowd of demonstrators, who went on a rampage through nearby streets. Buses and fire engines were set on fire, and at least three oil tanker trucks were commandeered and driven at the police, exploding with a huge roar.

At dawn, troops stormed the Royal Hotel with guns blazing, forced their way into the lobby and went room to room. Witnesses said the troops beat Thai demonstrators with batons even though they were offering no resistance and hauled them out to the street to be arrested. Journalists were held at gunpoint for several hours.

At least 1,500 demonstrators were held, their shirts ripped off and their arms tied behind their backs with the remains of their shirts. After their arrest, they were loaded into army trucks and driven away.

Earlier, for the first time, the violence spilled into parts of the city away from the protest site, located near the Democracy Monument. Motorcycle gangs rampaged through quiet areas of the business district, smashing police booths and looting some shops.

The street battles followed the arrest Monday afternoon of Chamlong Srimuang, the popular former governor of Bangkok who has spearheaded the opposition against Suchinda since last month.

Chamlong was taken from his command van, handcuffed and driven away in a jeep to an undisclosed military camp. The government announced that six other leaders of the demonstrations had also been detained.

The violence began Sunday evening when a crowd estimated at up to 200,000 people clashed with police during a demonstration demanding Suchinda’s resignation. Their chief objection to the former general is that rather than being elected to office, he was appointed to the job by military-backed political parties. Protesters set cars and trucks afire and looted a police station.

It was the worst violence in the country since 1976, when troops broke up a university demonstration, killing 46 students.

Suchinda declared a state of emergency early Monday morning in Bangkok and surrounding provinces, a move that banned gatherings of more than 10 people. But the measure was widely ignored.

A coalition of opposition parties held a news conference and appealed to the government to stop using violence to suppress the demonstrations. “Stop the provocation, stop banning news reporting, stop distortion of the truth,” said Chavolit Yongchaiyudh, leader of the New Aspiration Party.

One of the first casualties of the political strife was the Thai press, which had been among Asia’s most unfettered.

At 1:30 a.m. Monday, after the imposition of Suchinda’s state of emergency, an Interior Ministry spokesman appeared on national television and read an order to newspapers that they must “refrain from publishing articles or any other documents which carry content detrimental to national security, safety or inciting public unrest.”

The order caught many newspapers on deadline and left their editors perplexed about how to proceed.

The Bangkok Post, Thailand’s leading English-language daily, was so pressed for time that it blanked out its editorials and some news columns with news about the violence.