An appeals court in Cambodia on Thursday denied a second request for the release on bail of opposition leader Kem Sokha, who has been charged with treason.

The court appearance in Phnom Penh by Kem Sokha, head of the Cambodia National Rescue Party, was his first since his arrest last September. The hearing was held behind closed doors and journalists and other onlookers were kept away.

His prosecution by the government of Prime Minister Hun Sen is widely seen as part of a concerted effort to cripple the opposition ahead of a general election this year.

Kem Sokha's lawyer, Choung Choungy, said the court cited concerns for his client's security in denying bail.

The government has expressed fears of political protests by Kem Sokha's supporters. They have suggested, with no evidence, that violence might result.

Hundreds of riot police were deployed around the court, with several fire trucks and police trucks parked nearby.

The past several years have seen the opposition party face an onslaught of legal challenges from Hun Sen's government with the support of the courts, which are generally seen as favoring his ruling Cambodian People's Party. Court rulings forced former opposition leader Sam Rainsy to avoid prison by staying in exile and pressured him into resigning from his party.