Hospitals in Thailand's capital, Bangkok, say at least one person has been killed and many others wounded in a series of explosions near an encampment of anti-government protesters.
More than 70 people were reported wounded Thursday at the camp in the city's business district, which is packed with armed troops and diverse groups of protesters. Reports say at least five hand grenades exploded, prompting the closure of a nearby train station.
The protesters have besieged central Bangkok for weeks, trying the patience of citizens and business leaders. A coalition of groups gathered to drive the so-called Red Shirt protesters from the main retail and tourist district. Police separated the two sides.
The Red Shirt protesters have rallied for five weeks, demanding new elections and the resignation of Prime Minister Abhisit Vejjajiva.
A coalition opposed to the Red Shirts - called the Multi-Colored Shirts - has announced a mass rally for Friday.
Most of the protesters support former Prime Minister Thaksin Shinawatra, who was ousted in 2006. Mr. Thaksin lives in exile and faces a prison sentences on corruption charges in Thailand. He has a significant following among the country's rural and low-income population.
Mr. Abhisit came to power in December 2008, after months of massive anti-Thaksin protests by demonstrators known as the Yellow Shirts.
The military said soldiers will use tear gas, rubber bullets and live ammunition, if necessary, to remove the protesters. But Army Chief General Anupong Paochinda has been reluctant to use arms fearing renewed bloodshed.
An April 10 clash between the Red Shirts and Thai security forces left at least 25 people dead, and 850 others injured.
Some information for this report was provided by AP.