A Guatemalan court has convened for a fourth attempt to try former dictator Efrain Rios Montt on charges of genocide and crimes against humanity.

The 89-year-old ex-general is accused in the killings of nearly 2,000 indigenous Ixil Guatemalans by soldiers during his 1982-83 rule.

Rios Montt was convicted at a previous trial in 2013 and given an 80-year prison sentence. But that was swiftly overturned and a new trial ordered. Since then, the case has twice been delayed by legal appeals.

Rios Montt has been declared unfit for a regular trial due to dementia. So the special proceeding that opened Wednesday in the capital can determine his guilt or innocence, but would not result in any punishment if he is convicted.