Rights groups accuse both rebels and security forces of human rights violations including killings, torture, rape and kidnappings during a decade of Maoist insurgency that killed more than 13,000 people.

Three days ago, the guerrillas agreed to place their weapons under UN supervision and share power. They also agreed to form a truth and reconciliation commission to investigate human rights abuses committed by both sides during the insurrection.

"This agreement sets the foundation for a peace process and democratic transition in which the protection and promotion of the human rights of all Nepalis must be central," Louise Arbour, the UN High Commissioner for Human Rights, said in a statement.

"It is essential that the parties translate their commitments into meaningful actions to end abuses."

Arbour called for prosecution of serious human rights violations so that community trust is restored in the rule of law and future abuses are prevented.

The rebels, who fought to bring down the monarchy, have been accused by the UN of parallel "law enforcement activities". International media watchdog Reporters Without Borders has accused the Maoists of remaining intolerant of media criticism.