BANGKOK, July 24: Thai police said on Tuesday they could seek arrest warrants for up to 18 protest leaders suspected of instigating clashes with police at a weekend anti-coup rally.

Six people have already been arrested over Sunday night's violence, when more than 100 people were injured as protesters clashed with police who tried to block their march through central Bangkok.

Investigators on Tuesday were questioning witnesses and reviewing videotapes and photographs to determine if anyone else should be arrested over the first violence since last year's military coup.

“We may seek warrants for up to 18 protest leaders, who could be arrested immediately after the warrants are issued,” police Colonel Santi Klanbutr said. Police declined to name the possible suspects.

Anti-coup protesters, mainly supporters of ousted prime minister Thaksin Shinawatra, have been staging small rallies every night since early June to demand immediate elections and the resignation of the junta.

The protests had been losing steam since the junta earlier this month 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.

The protesters have also begun rallying against the proposed constitution, and have vowed to continue with their nightly demonstrations despite the clashes last weekend.—AFP