Seventeen people have been sentenced to death by an Egyptian military court over their involvement in bomb attacks on Coptic Christian churches.
A further 19 people were handed life jail terms over the attacks, which took place in 2016 and 2017, state news agency Mena reported on Thursday.
The Islamic State (IS) group said its militants were behind the suicide bombings that killed dozens of people.
Amnesty International described the death sentences as "grossly unfair".
"But handing out a mass death sentence after an unfair military trial is not justice and will not deter further sectarian attacks," it added.
The human rights group said that those accused of carrying out the church attacks in Egypt should be "retried in a civilian court in proceedings that comply with international human rights law".
Since 2014, Egyptian authorities have sent more than 15,000 civilians to military courts, which activists say do not provide even the limited due process protections.
As part of the Egyptian military court's sentencing on Thursday, a further 10 people were handed prison terms of between 10 and 15 years for their involvement in the attacks, officials said.
All of the sentences are subject to appeal.
An attack on a cathedral complex in the Egyptian capital Cairo the previous December left at least 25 people dead.
Egypt's Coptic Christians, who make up about 10% of the country's population, have often been targeted by Islamist militants.