Amnesty International says Cameroonian security forces have unlawfully killed dozens of civilians and tortured and forced the disappearances of others in mass arrests of suspects in fighting the Boko Haram Islamic insurgency.

A report published Thursday accuses forces operating in Cameroon's Far North province, bordering northeast Nigeria, of crimes under international law.

The London-based group says Cameroon's government and security chiefs have not responded to its requests for information about the allegations and missing people and its calls for investigations.

The Associated Press has quoted refugees who fled across the border into Nigeria as saying that Cameroonian troops were indiscriminately killing civilians and looting and destroying property.

Amnesty says it interviewed more than 160 people including victims, witnesses and a senior military officer during three trips to Cameroon in 2015.