A second humanitarian group is suspending migrant rescues in the Mediterranean Sea due to Libyan threats.

Germany-based Sea-Eye said Sunday that "with a heavy heart" it was forced to halt its ship's rescue activity for its crew's safety.

A day earlier, NGO Doctors Without Borders similarly cited Libyan threats in saying it's suspending sea rescue activities.

Libya has warned that it's extending its own search-and-rescue area to beyond the 12-mile limit Italy and other countries consider the boundary of Libyan territorial waters. A Spanish NGO rescue ship reported that the Libyan coast guard last week fired warning shots at them while the vessel was in international waters.

Humanitarian groups say migrants returned to Libya risk inhumane treatment.

Italy's foreign minister says fewer smuggler boats mean less earnings for human traffickers.