Fifteen bodies were found on a beach near the Libyan city of Sabratha, some of them burned, the Libyan Red Crescent said.
The group did not identify the dead or say how they had died, but human rights groups said they were likely migrants.
After being notified by authorities, Red Crescent volunteers recovered the bodies and took them to the city morgue, the group said.
Some were found inside a burned-out boat while others were nearby, it said.
Photos apparently showing the boat on fire were widely shared online.
Libya was a key route for clandestine migration towards Europe even before the 2011 uprising that overthrew dictator Moamer Kadhafi.
Since the start of the year, more than 14,000 migrants have been intercepted and returned to Libya, the International Organization for Migration (IOM) said Monday.
At least 216 people have died attempting the crossing and 724 are missing and presumed dead.
Source: NAM NEWS NETWORK