BANGKOK (AP) — Security forces and agitated protesters faced off at a major intersection Friday morning after bloody grenade attacks rattled Thailand's chaotic capital — a scene of tense, weekslong confrontations between die-hard demonstrators and a wavering government.

Three people were killed and 75 others wounded in the late-night attacks, according to Deputy Prime Minister Suthep Thaugsuban. Attackers shot five M-79 grenades from near where the anti-government Red Shirt protesters have been encamped and the blasts struck areas where curious onlookers and counter-demonstrators have gathered to shout at the Red Shirts, but Suthep stopped short of directly blaming the Red Shirts for the attack.

He urged people who had been demonstrating against the Red Shirts to leave the area for their own safety.

The first three blasts struck an elevated train station on Silom Road, the capital's financial district, where soldiers have been garrisoned since Monday. Grenades punched two holes in the platform roof, and passengers were rushed away down the station's stairs by soldiers who were stationed there.

Two more blasts about 30 seconds later struck the street intersection that is filled with counter-protesters who oppose the Red Shirts, as well as bystanders.

The train station blasts wounded at least two people. Chaos ensued after the second blasts, as the scores of wounded were treated and carried to ambulances, and police and soldiers began to clear the area. The front window of the sandwich shop was shattered, and a pool of blood was on its stoop.

"The authorities are conducting an investigation, but it's too soon to give any conclusion," said government spokesman Panitan Wattanayagorn. "This is the work of the terrorists that the government has always been wanting to get rid off. They have been hiding in several areas."

By morning, police and soldiers stood guard at the mouth of Silom Road, the capital's financial district, while across the intersection, Red Shirts screamed slogans and brandished sharpened bamboo staves. Morning traffic on the normally jammed road was light and fewer workers were seen headed for their offices.

The Red Shirts consist mainly of poor rural supporters of former Prime Minister Thaksin Shinawatra and pro-democracy activists who opposed the military coup that ousted him in 2006 after months of demonstrations by the Yellow Shirts.

The Red Shirts believe the government of Prime Minister Abhisit Vejjajiva is illegitimate because it came to power under military pressure through a parliamentary vote after disputed court rulings ousted two elected pro-Thaksin governments. They want Parliament dissolved and new elections held.

On Thursday, the army warned that time was running out for the Red Shirts to clear the streets, saying soldiers would crack down soon.

"To take people in Bangkok hostage is not right," army spokesman Col. Sansern Kaewkamnerd warned the Red Shirts. "Your time to leave the area is running out." The army has issued several warnings that it will move to break up the protests if they are not ended voluntarily. They are already in violation of several laws, including a state of emergency.

In a previous paroxysm of violence, 25 people were killed and more than 800 wounded on April 10 when the army sought to clear out Red Shirt protesters from an encampment in another part of the capital.

Masked gunmen opened fire on the soldiers with military weapons, triggering a lengthy street battle. The government sought to blame that violence on "terrorists," whom they tried to distinguish from the mainstream Red Shirts but didn't otherwise identify.

Since the protests in the capital began March 12, more than two dozen grenade attacks and bomb explosions have rocked the city. Nobody has yet been apprehended, giving rise to rumors and speculation, including that the some of the attacks were the work of renegade army officers either seeking to provoke the Red Shirts of settle scores within the fractious military.

Culpirts in violent incidents related to Thai politics are rarely brought to justice. There have still been no arrests, for example, in mysterious bombings on New Year's Eve 2006.

Suthep, who heads the government's Center for the Resolution of Emergency Situation, expressed sorrow over the casualties. "The government has tried to set up measures to protect the people by sending security forces in to protect people," he said.

He asked the people who had been protesting against the Red Shirts to leave the area for their own safety. Many did, but a few dozen returned later to resume throwing rocks and bottle at the Red Shirts, who have erected a formidable looking barrier of sharpened bamboo sticks and old tires atop which their guards perch.

Behind the Red Shirts' line is their redoubt, which extends for more than a mile (2 kilometers) up to another intersection, where tens of thousands of supporters gather around a stage to hear nearly nonstop speeches. They have been camped out on the capital's streets for almost six weeks.

Across from the Red Shirt wall before the blasts were several police trucks, dozens of police in riot gear, and a few hundred anti-Red Shirt demonstrators.

The anti-Red Shirt group includes office employees, middle class families, academics, some low-wage workers and members of the Yellow Shirts, a group that supports the current government and who themselves rampaged through Bangkok and seized the city's airports two years ago.

Although some are genuinely aggrieved by the inconveniences wrought by the protests, many seem to have primarily political objections to the Red Shirts, including claiming the movement is directed against the country's widely revered monarch. A songsheet distributed to followers included hateful right-wing songs used in military-backed anti-communist campaigns of the 1970s.

Siripan Nogsuan Sawasdee, an associate professor of political science at Bangkok's Chulalongkorn University, said she did not wish to speculate on who may have been behind the bombings.

"But the situation could provide a good excuse for the government to use force against the Red Shirt protesters," she said.

The emergence of rival groups such as those who have been demonstrating against the Red Shirts has made the situation "more provocative,", and their goals were not clear, she added.


Associated Press writers Jocelyn Gecker, Denis D. Gray and Grant Peck contributed to this report.