PHNOM PENH: A Cambodian court on Tuesday jailed a university student for 18 months for inciting crimes in an anti-government Facebook post that called for regime change.

Facebook is popular in Cambodia, where disenfranchised citizens have increasingly turned to the Internet to highlight alleged state abuses and demand political reforms.

Kong Raya, 24, was the first Cambodian convicted of using social media to attack the government of long-serving Prime Minister Hun Sen, who has warned that online critics could be traced and arrested in a matter of hours.

"There's nothing to be surprised about. This is how the court works," Raya, who looked unshaken by the verdict as he left the courtroom flanked by guards, told reporters.

Raya was charged in August for urging the public to join his "colour revolution" to "change the vulgar regime".

In his Facebook post he said he was willing to go to prison or die for his cause. How he intended to pursue it was never made clear and his call failed to garner public support.

Hun Sen, who started using Facebook in September last year, is one of its biggest fans. He encourages Cambodians to send him their problems and has taken credit for solving them.

Am Sam Ath, an activist with Cambodian rights group Licadho, said Raya's posting caused no turmoil or damage to society.

"This verdict is a message, a threat to other youths and people who dare to express personal opinions," he said.