The latest draft legislation to address wartime abuses still makes it difficult to prosecute serious crimes, Human Rights Watch and the International Commission of Jurists said in a joint statement.

The tiny Himalayan nation has been rebuked for repeated delays in implementing a peace process more than a decade after fighting with Maoist rebels ended in 2006.

In 2015, the Supreme Court of Nepal ruled that laws passed by the government to remedy war-era grievances did not meet international scrutiny.

But a fresh amendment currently under consultation has done little to close these loopholes, rights groups said.

Crimes like torture and enforced disappearances remain undefined, meaning major offenders may slip through the cracks.

"For a successful, internationally accepted process, the authorities in Nepal should focus on providing justice to victims, not engage in trying to get perpetrators off the hook," said Human Rights Watch Asia director Brad Adams.

A provision in the proposed legislation for community service as an alternative punishment to prison time has riled campaigners who say it amounts to impunity.

"We've waited years, but the draft is still incomplete and fails to satisfy the victim's demand for justice," Bhagiram Chaudhari, President of Conflict Victims Common Platform told AFP.

More than 60,000 complaints have been filed with two commissions set up to investigate crimes committed by security forces and Maoist insurgents during the decade-long conflict.

Rights groups say both commissions have been hamstrung by a lack of funding and political will, and just a handful of cases have appeared before a court.

More than 17,000 people were killed, 1,300 disappeared and thousands displaced during the war which ended with a peace deal between Maoist insurgents and government forces.

The pact also heralded the end of the Hindu monarchy, which was abolished after the former rebels won power in Nepal's first post-war national elections.