BANGKOK, July 22: Protesters demonstrating against last year's coup in Thailand clashed with police on Sunday as riot police used tear gas and shields to break up thousands of people marching through Bangkok, officials said.

The demonstration was the most violent one yet against the junta that seized power in a coup last September, but police said only a few people suffered minor injuries.

Three people were arrested, but police said they would seek arrest warrants for the protest leaders on Monday.

The clashes began after about 5,000 protesters — mainly supporters of ousted prime minister Thaksin Shinawatra — began marching from the plaza where they have been holding nightly rallies since early June, according to police.

Police blocked their way as they headed to the nearby home of Prem Tinasulanond, the king's top adviser, who has been accused by Thaksin's allies of masterminding the coup last September.

Protesters began throwing rocks and bottles of water, but police responded with tear gas and pressed back the crowd with their shields. The standoff lasted about two and a half hours.

“Police will issue arrest warrants for the protest leaders tomorrow, as they have created some disturbances tonight,” Bangkok's deputy police chief Major General Pongsak Eaimorn said.

The spokesman for the junta, Colonel Sunsern Kaewkumnerd, said the situation was under control and that the injuries were minor.

“Demonstrators tried to provoke policemen. They threw rocks and bottles of water at the police,” he said.

“The situation is not a concern. I believe police can keep it under control,” he added.

Thaksin's allies have staged the protests to demand that the junta step down and that elections be held immediately. The demonstrations have been largely peaceful, and have rarely attracted more than a few thousand people.

Earlier this month, the junta unveiled a new constitution that they say will guide Thailand towards elections before the end of the year.

The charter is set to go to a referendum next month, in what will be the junta's first test at the ballot box.

Thaksin, who has lived in exile since the coup, has been barred from standing in the elections.

A military-appointed court has disbanded his political party, while anti-corruption authorities have frozen more than 1.5 billion dollars of his assets.—AFP