TRIPOLI (Reuters) - Migrants refusing to leave a cargo ship docked in Libya said on Wednesday they would rather die than be returned to land, as the coast guard began disembarking some of those on board.

In the first documented case of its kind, the migrants have been stranded on the ship since it intercepted them off Libya’s western coast on Saturday and brought them to the port of Misrata.

A Sudanese on board, Biktor, said his brother and friend had both died at the hands of smugglers in Bani Walid, a smuggling hub south of Tripoli.

“How come you want me to leave the ship and stay in Libya?” the 17-year-old said. “We agree to go to any place but not Libya.”

More than half a million migrants crossed the Mediterranean from Libya to Italy in 2014-2017, before heavy Italian pressure resulted in the disruption of smuggling networks on the North African country’s coast and the withdrawal of charity rescue ships.

Libya’s EU-backed coastguard has also stepped up interceptions, returning migrants to detention centers notorious for poor conditions and drawing sharp criticism from human rights groups.

Fourteen of the migrants docked at Misrata, including a Sudanese mother and her baby, agreed to come off the ship late on Wednesday, aid workers and a coast guard officer said.

Libyan authorities were still negotiating with the other migrants, who have so far refused to disembark.

“I was stopped by this ship and I thought I would be sent to Malta or Italy,” Mohamed, a 19-year-old from Sudan’s war-torn Darfur region, told Reuters by phone before the disembarkation started.

“I prefer to die but not to be returned to Libya ... it’s a prison.”

The migrants are of Eritrean, Somali, Bangladeshi and Sudanese nationality and include a number of children.

Some required urgent medical assistance, and the Libyan coast guard has allowed international aid agencies to provide treatment and food supplies on board, said Julien Raickman, Libya mission head for Medecins Sans Frontieres (MSF).

He called for a peaceful resolution and said the most vulnerable migrants should be offered an alternative to detention.

“We talked to people who have suffered torture on the migration route and it seems abnormal that the United Nations cannot propose an alternative for them,” Raickman said.

After migrants are returned to Libya they are screened by U.N. agencies and given basic assistance before being taken to government-affiliated detention centers, where they sometimes cannot be tracked and may re-enter smuggling networks.

The U.N. refugee agency, which has resettled nearly 1,000 migrants from Libya this year, said in an statement it was “closely following up on the situation of those already disembarked” and “continues to advocate for alternatives to detention”.