More than 200 policemen with bomb detectors and five sniffer dogs were deployed around the court where some 400 of Thaksin's supporters waited, many holding portraits of the former leader over their heads.

"The defendant pleaded not guilty of the charges," chief judge Thongloh Chom-ngam told the court, which set the next hearing for April 29. It also excused Thaksin from having to appear at every hearing, as requested by his lawyer.

"We can prove our innocence," said Thaksin, who was ousted in a September 2006 military coup for alleged corruption and abuse of power.

When he emerged after the hearing, some of his supporters burst into tears while others cheered him, shouting "Thaksin, fight, fight."

"Never mind, everything will be OK," Thaksin told one female supporter who cried as she hugged him.

Thaksin's return has stirred the Thai political scene because of suspicions that he will seek a return to power and try to settle the score against those who deposed him.

He has insisted, though, that he has no interest in returning to politics and has said he plans to devote himself to charity work, sports and his family.