The large number of decomposing bodies still under collapsed structures and in floodwaters in Derna city has raised concerns about the risk of disease for survivors.
Libya's Interior Minister Emad al-Trabelsi on Thursday told Al-Hadath TV that health authorities were investigating health hazards in the city and would make a decision on the threat of a potential outbreak.
He said electricity has been connected to some areas of Derna and work was under way around the clock to restore services.
The minister put the official death toll at 3,000 with more than 2,800 people still missing.
There is discrepancy over these figures, with Libya's ambassador to the UN saying about 6,000 people have died so far. The Red Crescent put that number higher, at 11,300.