Thousands of troops were deployed in the Thai capital yesterday to reinforce security amid fears that protests against the country's army-backed government could again turn violent. Most of the 2,100 troops were guarding Sanam Luang plaza in central Bangkok, a venue of daily rallies demanding the ouster of the junta, which came to power after last year's coup overthrowing prime minister Thaksin Shinawatra.

"We are deploying troops to ensure security for the public," said the regional army commander, Lieutenant General Prayuth Chan-ocha, adding that extra troops were also deployed around the prime minister's office.

In case of emergency, the military was ready to send an extra 2,200 troops for security, he said. Police said 300 officers were stationed around the plaza.

Thailand's junta chief, General Sonthi Boonyaratglin, ordered the troop deployment on Friday after more than 100 anti-coup protesters were injured in clashes with police last Sunday.

The clashes were the first violence since the bloodless coup in September 2006 and came as campaigning got underway for an August 19 referendum to approve an army-backed constitution.

Police arrested nine protest leaders over the clashes, but one was released late Friday on bail.

The eight, a mixture of academics supporters of Thaksin, have been held since Thursday, when they were charged with organising an illegal demonstration and instigating unrest.

"The protesters can be detained for up to 48 days," Police Colonel Supisarn Bhakdinarinath said, although he said if investigations into Sunday's clashes with police were completed quicker, their pre-trial detention would be shorter.

They have denied the charges and refused to apply for bail.

Authorities have repeatedly warned that the government could impose a state of emergency in Bangkok if more violence breaks out at anti-coup protests. But protest organisers said they would continue to stage the rallies to voice opposition to military rule.

"We have the right to give information to the public and will continue our campaign to urge people to vote against the constitution in the referendum," said Pratheep Ungsongtham Hata, leader of an alliance of democracy advocates and Thaksin supporters.

While taking a tough line against protesters, the government has insisted that the anti-coup rallies will not derail the constitutional referendum next month.

The military says the new charter will clear the way for elections by the end of the year, but opponents fear it will provide ways for the army to maintain an influence over government through powerful appointees.

PHOTO CAPTION

Thai policemen stand guard at a barricade during a march against the Royal Thai army in Bangkok in this June 23, 2007 file photo. (Reuters)

Al-Jazeera