Thai "reds," "yellows" rally on Bangkok's streets

BANGKOK (Reuters) - Thousands of Thais held color-coded "red" and "yellow" protests in Bangkok on Sunday, underlining persistent anti-government sentiment and deep political divisions ahead of an election planned this year.

The "red shirts" called for the release of 18 of their detained leaders and their rival "yellow shirts" demanded Prime Minister Abhisit Vejjajiva's resignation over his handling of a long-running border dispute with Cambodia.

The rallies were staged ahead of an election that Abhisit says could take place in the first half of the year. On-off anti-government campaigns since 2005 by two groups with a history of, at times, violent protests point to a rocky road for Southeast Asia's second-biggest economy.

The two rallies also took place in defiance of the Internal Security Act (ISA) invoked last Tuesday and banning protests in main government and commercial areas.

There was a heavy presence of riot police, but no attempt was made to block the demonstrators, who protested peacefully.

Last year saw some of the worst political violence in modern Thai history during a 10-week protest and sit-in in Bangkok by "red-shirts," most of whom support ousted former premier Thaksin Shinawatra.

Gunmen clashed with soldiers on the streets and eventually the military crushed the protest. Ninety-one people were killed and more than 1,800 wounded.

Eighteen "red shirt" leaders have been detained since then and their supporters massed on Sunday outside the Criminal Court, which will make a ruling on a bail appeal on February 21.

"We are here to call for justice," 'red shirt' leader Thida Thavornseth told reporters outside the court.

"We're not planning to break into the court. We just want to show our support to all the leaders who are still in prison."

ELECTION BY JUNE?

They later moved to the Democracy Monument in the city's old quarter, just over a kilometre (half a mile) from a small, two-week protest held by the yellow-shirted People's Alliance for Democracy (PAD).

The government agreed to use the ISA following concerns the PAD might try to take over its offices. However, its support appears to be dwindling.

The PAD was once an ally of Abhisit's ruling Democrat Party but has turned against him in the past few months over what they see as his failure to act decisively, in particular over a border dispute with Cambodia.

Four days of clashes between Thai and Cambodian forces erupted on the border early this month.

The "red shirts" are angered by the slow progress of an investigation into last year's violence and they have submitted a petition to the International Criminal Court asking for it to intervene, concerned the inquiry will be a "whitewash.

Abhisit, whose term comes to an end in December, said last week he planned to dissolve parliament and hold elections by June, if the country was peaceful.

Analysts say financial markets would welcome polls which could restore stability in Thailand and its $265 billion economy.

But a big risk is that one or both of the rival main parties rejects the result and turbulence returns, bringing the possibility of more violence or even military intervention.

(Additional reporting by Ploy Ten Kate; Writing by Martin Petty; Editing by Robert Birsel and Ron Popeski)