Medical charity Médecins Sans Frontières/Doctors Without Borders say over 100 migrants and refugees have escaped from human traffickers, who held them captive in a clandestine prison in Libya.

It says they were shot at while attempting to flee.

Some 25 of the injured were referred to General Hospital of Bani Walid.

Among them, 18 suffered minor injuries and received first aid and dressing.

Seven of them were hospitalized for further care due to severe gunshot wounds and multiple fractures.

Survivors told MSF of at least 15 people who died in the escape - however this number has not been confirmed.

They also reported that at least 40 people - mostly women - remained behind because they were afraid to escape, or could not manage to do so.

4/ At general hospital in Bani Walid #MSF medics assisted in stabilization of 25 wounded with 7 people hospitalized due to gunshot wounds and multiple fractures sustained during escape. #MSF donation of medical supplies to hospital underway. pic.twitter.com/4AWwopu91I

— MSF Sea (@MSF_Sea) May 25, 2018

The survivors are mostly teenagers from Eritrea, Ethiopia and Somalia who were trying to seek asylum in Europe.

They reported they were victims of human traffickers, who had sold them multiple times between Bani Walid and Nesma.

Some of the survivors told MSF teams they had been held captive for up to three years.

The charity said: "Scarred bodies, visible marks of electrical burns, and old infected wounds give an idea as to the ordeal they have suffered.

"People are traumatised, and the majority are unaccompanied minors."

Christophe Biteau, MSF head of mission, said: "All necessary measures must be taken to ensure patients can access the required treatment and to protect these extremely vulnerable people from further harm after surviving such atrocities.

"Arbitrary detention cannot be a solution. They are in urgent need of protection and assistance".