By Amy Sawitta Lefevre
BANGKOK (Reuters) - Protesters seeking to oust Thailand's government broke into the grounds of an air force compound on Thursday where the acting prime minister was meeting the Election Commission to fix a date for new polls, forcing him to flee.
The disruption of acting Prime Minister Niwatthamrong Boonsongphaisan's efforts to organize an election came hours after gunmen attacked anti-government protesters, killing three.
The turmoil comes as the government loyal to ousted former premier Thaksin Shinawatra squares off with opponents backed by the royalist establishment over who should be prime minister, in the latest phase of nearly a decade of rivalry.
Hundreds of protesters converged outside an air force school in north Bangkok after word spread that Niwatthamrong was meeting commission officials there. They had put off talks at another venue the previous day because of security fears.
"We are here to tell Niwatthamrong that there is no point standing in our way," Chumpol Jumsai, a leader of the anti-government protesters, told the crowd from on top of a truck shortly before hundreds of protesters evaded police and streamed through a side entrance of the compound.
Commission member Somchai Srisutthiyakorn said the meeting was being abandoned and Niwatthamrong was leaving. "We will have to meet another day," he said.
The government sees a general election as the best way out of a crisis that threatens to tip Southeast Asia's second-biggest economy into recession and has even raised fears of civil war.
Its enemies know the government would be highly likely to win a poll, and want electoral reform aimed at ending the influence of former telecommunications tycoon Thaksin before another vote is held.
Somchai later told Reuters a tentative date of July 20 for the election looked improbable,. "We may have to push back the polls," he said.
Earlier, a small group of men armed with guns and grenades attacked anti-government protesters near the Democracy Monument in Bangkok's old quarter killing two people on the spot, with a third dying later of his wounds. More than 20 people were injured, police said.
Paradorn Pattanathabutr, a security adviser to the prime minister, said he suspected the attack was a reaction to pressure by the anti-government side to force the Senate to appoint a new prime minister.
It was the most serious incident since five people were killed and dozens wounded in clashes on February 18, when police made their most determined effort to clear demonstrators.
Twenty eight people have been killed and hundreds injured since the protests began in November.
The army has a long record of intervening in politics but military chiefs have stayed aloof from this crisis, insisting that politicians must sort out the dispute.
However, more violence would raise the possibility of the military feeling compelled to step in to restore order.
Thaksin won huge support among the rural and urban poor but made enemies of the Bangkok-based elite who saw him as corrupt and authoritarian, and accused him of being disrespectful to the monarchy.
Thaksin denied that, but he was deposed in a 2006 coup and has lived abroad since 2008 to avoid a jail term for graft charges that he says were politically motivated.
Nevertheless, he has exerted influence through his loyalists including his sister, Yingluck Shinawatra, who led a pro-Thaskin party to a resounding election victory in 2011.
Yingluck lost her job as prime minister last week when the Constitutional Court ruled she had abused her power, but her caretaker government remains in office.
The anti-government protesters say Thaksin wins elections through money politics and they want the Senate to depose the remnants of Yingluck's caretaker government through the appointment of a "neutral" interim prime minister.
"If, by Friday ... the Senate fails to come up with a solution then the people may have to seize power and set up a people's assembly on their own," anti-government protest leader Suthep Thaugsuban, a former deputy prime minister in a pro-establishment government, told supporters late on Wednesday.
The Shinawatras' "red shirt" supporters, who are holding a sit-in protest on Bangkok's western outskirts, have warned of violence if the caretaker government is ousted.
"Suthep has said he will seize power for the people. Well, if he seizes power then we will take it back," Natthawut Saikua, a leader of the pro-government activists, told Reuters.
(Additional reporting by Apornrath Phoonphongphiphat and Aukkarapon Niyomyat; Writing by Robert Birsel; Editing by Alex Richardson)