LAGOS, Nigeria (AP) — At least 10,000 civilians have died in Nigerian military custody since 2011 after being detained in connection with the Boko Haram insurgency in northeast Nigeria, Amnesty International charged Tuesday.

Many of the victims died at the “infamous Giwa Barracks,” in Maiduguri, said Amnesty in a report, adding that “in April 2017 alone, 166 corpses were transferred from Giwa to the mortuary.”

“Severe overcrowding, scarce food and water, extreme heat, infestation by parasites and insects, and lack of access to adequate sanitation and health care are among the litany of violations at Giwa,” said Amnesty.

Older people are not spared “the military’s widespread unlawful detention” of those fleeing Boko Haram areas — even without any evidence that the person was linked to the armed group, much less involved in violence, said the report.

The rights group said it reviewed more than 120 images of corpses brought from the barracks to a local mortuary and spoke to individuals with direct knowledge of the detentions who estimated that up to 25% of those who died were older men.

The report is the latest to be made by international rights groups on alleged human rights abuses by the Nigerian military in northeast Nigeria where it is fighting the Boko Haram insurgency.

The military has not responded to the report but it has in the past denied similar charges of human rights violations. Boko Haram and ISWAP have also been accused of widespread human rights violations.

Boko Haram and the breakaway faction, the Islamic State West Africa Province, are fighting to impose strict Islamic Shariah rule in Nigeria.

Thousands have been killed in the more than 10-year-old insurgency, more than a million people displaced.