A court has denied an amnesty for a former U.S.-backed dictator who presided over one of the bloodiest periods of Guatemala's civil war, allowing his trial to continue.

The Center of Legal Action in Human Rights, which is a plaintiff in the case, says the court informed it of its decision on Jose Efrain Rios Montt's appeal on Wednesday.

This is the fourth time the courts have denied Rios Montt an amnesty. His lawyers have sought to block the trial, arguing that he is protected by an amnesty law.

Rios Montt, 86, is facing trial on charges he ordered the murder, torture and displacement of thousands of Mayan Indians.

During the 1960-96 civil war, more than 200,000 people were killed or went missing, according to the United Nations.