By Martin Petty
BANGKOK (Reuters) - A series grenade blasts shook Bangkok's business district on Thursday, wounding at least 50 people and heightening tensions during a showdown between thousands of troops and anti-government protesters.
Five explosions hit the area packed with heavily armed troops and studded with banks, office towers and hotels, seriously wounding at least four people, including two foreigners, according to witnesses, hospital officials and an army spokesman.
Hundreds of troops, many armed with M-16 assault rifles, have poured into the area since Monday to stop anti-government protesters who have formed a barricade at an intersection leading into the bustling district also known for racy go-go bars.
The blasts were caused by M-79 grenades, Col. Sansern Kaewkamnerd told Reuters. The same type of grenade -- fired with a shoulder-mounted launcher -- hit troops during a bloody clash with protesters that killed 25 people on April 10.
One explosion hit outside the headquarters of Charoen Pokphand Group, Thailand's biggest agribusiness group. Another landed near the Dusit Thani Hotel.
Nearly a dozen ambulances streamed into the area. Many of the victims were wounded by shrapnel. Television footage showed blood splattered across sidewalks, office windows smashed and a chaotic scene as panicked residents carried the injured into ambulances.
The grenades were fired in an area where about 500 pro-government protesters had gathered, Sansern said.
Not far from the explosions, tens of thousands of red-shirted supporters of former prime minister Thaksin Shinawatra have fortified their redoubt in a Bangkok commercial district with home-made barricades, expecting the army to evict them any time.
After the blasts, troops blocked off roads with razor wire and trained their guns in the air looking to rooftops and an overhead railway system.
The army earlier on Thursday warned it would forcibly disperse the mostly rural and urban poor red shirts who have led nearly seven weeks of protests demanding elections.
"Your days are numbered," army spokesman Sansern Kaewkamnerd said on Thursday. "If you leave now, you won't be prosecuted. But if you wait until the security forces enter, you will be prosecuted. You could also be hit by stray bullets during clashes between the security forces and heavily armed terrorists."
Red shirt leaders say another attempt to evict them would be futile. They say they will only leave Bangkok when Prime Minister Abhisit Vejjajiva announces early elections.
Some 20,000 red shirts have occupied a roughly 3 square-km (1.9 mile) area of central Bangkok, setting up a self-contained village in an upscale shopping and hotel area.
"I am not afraid," said Saisunee, 23, a waitress in Bangkok who was part of the red shirts. "There are lots of people here. I don't think the army can dismiss us," she said when asked if the army's ultimatum frightened her.
YELLOW SHIRTS TO RALLY
A pro-government "multi-coloured" group said it plans to gather 50,000 people for a rally on Friday at Government House in central Bangkok to voice their opposition to the red shirts, splitting the capital into opposing groups.
Many of Bangkok's 15 million people are getting fed up with weeks of protests that have forced hotels and malls to close, and threaten livelihoods.
Any attempt to disperse the red shirts risks heavy casualties and the prospect of clashes spilling into nearby high-end residential areas -- or with the "multi-coloureds."
The "red shirt" uprising showed the first signs of spreading beyond Bangkok to the protesters' stronghold in the northeast after they blocked a train carrying troops and military vehicles.
In the province of Khon Kaen, about 400 km (249 miles) from Bangkok, red shirts agreed on Thursday to let a military train proceed -- if it takes along 10 of them to make sure the train goes to its intended destination in southern Thailand and not bring reinforcements to Bangkok.
About 200 red shirt protesters rallied in front of the regional headquarters of the United Nations in Bangkok on Thursday requesting peacekeepers be deployed to provide security. Police made no move to stop them.
About 50,000 troops have been deployed in the capital and can use live ammunition if necessary for self-defence.
The crisis has decimated Thailand's important tourism industry and was the key reason the central bank left interest rates at a record low on Wednesday.
But Thailand's exports jumped 41 pct year-on-year in March, compared to 23 percent in February, indicating the protests have yet to punish the wider economy.
(Additional reporting by Nopporn Wong-Anan; Writing by Jason Szep. Editing by Bill Tarrant)
