Cameroon has forcibly returned 100,000 Nigerian refugees in breach of international agreements, Human Rights Watch (HRW) said in a report made public on Wednesday.
Cameroon is “punishing” refugees for Boko Haram attacks, HRW said.
The group, which investigates allegations of human rights abuses worldwide, said the report is based on interviews with more than 60 refugees.
It added that soldiers tortured, assaulted and sexually exploited Nigerian asylum seekers and denied them access to the UN refugee agency.
“The Cameroonian military torture and abuse of Nigerian refugees seems to be driven by an arbitrary decision to punish them for Boko Haram attacks in Cameroon and to discourage Nigerians from seeking asylum,” said HRW Associate Refugee Director, Gerry Simpson.
Cameroon has rejected similar accusations previously, saying Nigerians have returned willingly.
“Since early 2015, the Cameroonian authorities have summarily deported at least 100,000 Nigerians living in remote border areas back to war, displacement and destitution in Nigeria’s Borno state,” HRW said in the report.
“In carrying out these deportations, Cameroonian soldiers have frequently used extreme physical violence.”
Boko Haram militants have carried out attacks in north-east Nigeria, forcing residents to flee to Cameroon
Earlier this year, the UN refugee agency (UNHCR) criticised Cameroon for forcibly returning hundreds of refugees to north-east Nigeria.
It said the returns had “continued unabated”, despite the signing of an agreement ensuring that any returns would be voluntary.
The Cameroonian authorities have previously claimed that Boko Haram militants have been entering the country disguised as refugees.