Amnesty International has called on the Guatemalan authorities to do more to provide justice for thousands of victims of the country's civil war.
More than 200,000 people - most of them civilians - were killed or disappeared between 1960 and 1996.
The group said that tens of thousands of cases have yet to be heard by the commission established to probe cases.
They said that without justice, Guatemala would not be able to "move forward from its dark past".
Amnesty called on the Guatemalan government to approve a law for a National Search Commission for the Disappeared.
Kerrie Howard, of the group's America's programme, said this commission was "essential to implementing the recommendations made by the country's Historical Clarification Commission 10 years ago".
A 1999 report by that commission found evidence of widespread human rights abuses and 669 massacres, many in indigenous villages, said Amnesty.
Ms Howard said its recommendations had been a "massive landmark for human rights in Guatemala" but it was now time "for the government to deliver some justice".
Amnesty said no high-ranking officials or officers have yet been brought to justice over the atrocities and the few investigations which have taken place have been "deplorably slow and inadequate".
"The Guatemalan authorities have the legal and moral duty to ensure that the crimes committed during the country's internal armed conflict, many of which constitute crimes against humanity, are investigated and that those responsible are brought to justice," said Ms Howard.
"The best way for the Guatemalan authorities to remember and honour the victims of abuse committed during the armed conflict is by ensuring that those who committed, authorised or planned those crimes are not able to evade justice."