Cambodia's Supreme Court on Friday denied bail requests for the 23 labor activists and garment workers who were arrested following violent clashes four months ago.

"The court decides not to grant bails to the detainees because the Phnom Penh Municipal Court has been proceeding with the trial of the defendants," said the verdict read by the Supreme Court's Presiding Judge Khim Pon.

"Therefore, the presence of the defendants is necessary."

Outside the court, dozens of labor and human rights activists protested against the court's decision.

The detainees, who are charged with intentionally causing violence and destroying property, were arrested during clashes between anti-riot police and protesters in January when they held violent protests to demand a higher minimum wage of 160 US dollars a month for the garment sector.

The clashes at that time left 4 people dead and dozens injured, and cost garment factories millions of US dollars.

Under the Cambodian law, the defendants could face up to five years in jail if they are convicted.

The Phnom Penh Municipal Court is scheduled to hear the case on May 20 after twice adjournments.