A rights group says Libyan authorities have committed "shocking abuses" against migrants detained on their way to Europe, leaving them with no choice but to risk the perilous crossing again.

Amnesty International said Tuesday that migrants who had been detained by the Libyan coast guard described being beaten, shot or sold to smugglers. The group said Christian migrants described being singled out for especially brutal treatment.

Amnesty warned that European plans to stop the flow of migrants by cooperating with Libya would come with a human cost.

Magdalena Mughrabi, the group's interim Deputy Middle East and North Africa Director, says "the EU has repeatedly shown it is willing to stop refugees and migrants from coming to the continent at almost any cost now, with human rights taking a back seat."