"The reason the traffic has become more deadly is that the traffickers are taking more risk, because there is more surveillance exercised by the Libyan coastguards," said Vincent Cochetel, UNHCR's special envoy for the central Mediterranean.
"They are trying to cut the costs: It costs them more to keep those people here longer in their warehouses, under captivity."
Libyan authorities intercepted or rescued 18,400 people between August last year and July this year - a 38 per cent increase from the same period of 2016 and 2017. Arrivals by sea from Libya to Europe plummeted 82 per cent in those comparable periods, to 30,800 in the more recent one.
UNHCR says a growing worry these days is deaths on land by people trying to get to Libya in the first place, or getting stuck in squalid, overcrowded detention centres: Many get returned there after failing to cross by sea to Europe.
"Many [then] disappear," Cochetel said. "Many are sold to militias, and to traffickers, and people employing them without paying them."
- AP