At least 20 dead bodies have been seen in the sea some 30 miles off the coast of Libya, Italy's Coast Guard said on Wednesday, as efforts to rescue some 1,700 people packed onto 15 boats continued.

Axar.az reports citing Reuters.

"About 200 people fell into the water when one of the boats listed dangerously," Coast Guard Commander Cosimo Nicastro told Reuters. "At least 20 dead bodies were spotted in the water."

Co-founder of humanitarian rescue group MOAS, Chris Catrambone, said on Twitter that many corpses had been brought on board their ship, and that toddlers were among the dead seen in the water.

The Coast Guard is calling in more ships to help with rescues, Nicastro said. Apart from the MOAS vessel, a tug boat was assisting in rescues coordinated by the Italian Coast Guard in Rome.