Bangkok: Thailand`s elite-backed "Yellow Shirts" called on Monday for a state of martial law to end anti-government protests as the rival "Red Shirts" blocked police convoys heading to the strife-torn capital.
The Yellows have said they will take action to "protect the country" if authorities do not deal with the thousands of anti-government Reds in the capital, stoking fears of factional violence.
Thailand`s revered king spoke on television for the first time since the protests broke out in mid-March, addressing a group of newly appointed judges. He did not address the ongoing crisis.
"Do your job with honesty. In this country there may be some people who forget their duty. You should be an example by working honestly and properly, your job is very important," King Bhumibol Adulyadej told the judges.
Thailand`s opposition has asked for an audience with the 82-year-old king, who has intervened in previous bouts of civil unrest.
Twenty-six people have been killed and almost 1,000 injured in the capital this month in Thailand`s bloodiest street violence in almost two decades.
The Reds are on alert for a crackdown by security forces on their fortified camp in the heart of Bangkok, where tensions remain high after a grenade attack late Sunday on the house of a former premier injured 11 people.
The movement, seeking immediate elections to replace a government it sees as elitist and undemocratic, said it would launch nationwide action to stop troops from travelling to the capital, which is under a state of emergency.
"Reds everywhere will stop police and army from coming to Bangkok," said one senior leader, Nattawut Saikuar.
Hundreds of security forces have been detained in a series of incidents, mainly in the northern stronghold of the Reds, mostly supporters of ex-premier Thaksin Shinawatra who was ousted in a 2006 coup.
On Monday, some 60 Red Shirts blocked the entrance of a border patrol police camp in a central province to prevent a company from leaving for Bangkok, triggering scuffles as police broke though the protest lines.
And on Bangkok`s northern outskirts, armed troops took up positions on a highway as they dispersed Reds who had set up a checkpoint, leading to several arrests.
A one-week deadline set by the Yellows for an end to the crippling protests expired with no end in sight and the movement called on its supporters to begin their own peaceful demonstrations.
"The prime minister knows well that in this situation military measures are needed because it was hard to resolve it through politics," said Suriyasai Katasila, spokesman for the Yellows` New Politics Party.
"There should be an announcement of martial law," he said.
Thailand is largely split between the mainly rural poor and urban working class Reds, and the Yellows who staged their own street protests that heralded a 2006 coup ousting their enemy Thaksin.
Yellow protesters in 2008 blockaded Bangkok`s two main airports, before a controversial court verdict removed Thaksin`s allies and allowed a parliamentary vote that brought in the current government.
Over the weekend Abhisit rejected an offer by the Reds to disperse if elections are held in three months` time and vowed to retake the protest site, without saying when.
The anti-government movement remained defiant after another day passed with no sign of a crackdown on their base, which has been fortified with barricades made from piles of truck tyres and sharpened bamboo poles.
As the stalemate dragged on, Nattawut said they would announce new plans Tuesday including for a march, but did not say when and where it would be.
Many of the anti-government protesters have begun shedding their trademark red clothing and wearing other colours to make themselves harder to identify.
Raising the pressure on Abhisit, the Election Commission submitted a case of alleged misuse of election grant money by his party to the Constitutional Court, which will consider whether to hold a hearing on the matter.
Earlier this month the commission called for his Democrat Party to be abolished over the allegation and a second case that centres on an alleged illegal political donation in 2005.