Migrant deaths have risen to record levels on the Libya-to-Italy smuggling route across the Mediterranean Sea. They generally attempt the crossing in flimsy inflatable craft loaded with small amounts of fuel which are intended to get them only as far as European rescue vessels stationed in international waters.
Libyan coast guard spokesman Ayoub Gassim said more than 500 migrants were rescued at sea on Friday and Saturday. The migrants' boats were 5-7 miles from the coast of Libya.
Gassim said the coast guard is seeing the smugglers use larger rubber boats in order to pile more migrants into the weak vessels — some taking on as many as 180 people.
"This is going to be even more disastrous to the migrants," Gassim added.
Last year a record 181,000 migrants crossed between Libya and Italy. More than 4,500 are known to have died.
Having largely closed off sea crossings between Turkey and Greece last year, the European Union is searching for ways to stem the flow of migrants from Libya.
Kate Brannelly and The Associated Press contributed.