Thai police suspect anti-government link to blast

BANGKOK (Reuters) - Thai authorities uncovered on Wednesday bomb-making material at the site of a suburban Bangkok explosion that killed four people and stoked fear of more political violence after mass anti-government protests this year.

The blast also wounded nine people when it went off in an apartment building in Nonthaburi province, north of Bangkok, on Tuesday evening. Police said investigations indicated a flat may have been used to assemble bombs.

They said evidence also suggested a link to a bombing near a Bangkok race track on September 26, one of 16 mysterious blasts that have shaken the capital and its surrounds since troops forcibly ended 10-week anti-government "red shirt" protests on May 19.

Most of the blasts have not caused injuries but have added to simmering tension in Bangkok over a five-year political crisis that has brought riots, deadly military crackdowns and the seizure of government offices and international airports.

Police said the explosion happened in a room rented by an anti-government protester from the northern city of Chiang Mai, a stronghold of the red shirt movement and hometown of its patriarch, ousted former premier Thaksin Shinawatra.

The man was among the dead, police said.

Defense Minister Prawit Wongsuwan said the identity of the tenant suggested red shirt radicals may have been involved.

"The renter of the room is a red shirt and it's possible it was linked to a more hardcore group," he told Reuters. "There is evidence it might have been politically motivated but the police should be given time to do their job."

The blast and a possible link to radical red shirts highlight stubborn risks for foreign investors who have plowed $1.7 billion into Thai stocks in the past two months.

EXPLOSIVE DISCOVERY

Based on the extent of the damage and presence of explosive residue, police said they suspected the blast could have been caused by up to 10 kg (22 lb) of TNT.

"Initial investigations showed it might have been a bomb-making accident," the national police chief, General Wichien Pojphosri, told reporters, adding that the components found suggested links to three attempted bombings in the province.

Also found was the explosive chemical ammonium nitrate, cooking gas canisters which have been used as bomb casings, an AK-47 rifle and a CD titled "new Thai state," a euphemism for republicanism in a country where discussion of the monarchy's role in politics is taboo and limited by tough lese majeste laws.

Wichien said the man who rented the room had taken part in the red shirt protests in April and May.

"He adored Thaksin very much and he had disappeared for four months," Buakam Muangma, his wife, told reporters in Chiang Mai, adding that her husband was shot and wounded in April's clash.

Nonthaburi is one of four provinces under emergency rule after the anti-government protests in Bangkok turned violent, claiming 91 lives and wounding nearly 2,000.

Jatuporn Prompan, an opposition member of parliament and anti-government protest leader, chided police and government officials for linking the blast to the red shirt movement.

"It is irresponsible at best and sinister at worst. They haven't presented any evidence," Jatuporn told Reuters.

(Additional reporting by Panarat Thepgumpanat and Pracha Hariraksapitak; Editing by Martin Petty and Robert Birsel)