At least 18 irregular refugees have died in a shipwreck off the city of Tobruk in eastern Libya over the weekend, and 50 are still missing, the International Organisation for Migration said, citing reports.

Ten survivors have been accounted for so far, the IOM said.

Tobruk is a coastal city near the border with Egypt.

A diplomatic source from the Egyptian consulate in Benghazi in eastern Libya told Reuters by phone that the migrants are from Egypt.

The diplomat said 10 bodies were identified and transferred back home, while the survivors were being held in an anti-illegal migration facility.

A Libyan Coast Guard official said the bodies of irregular refugees were found on Alaghila Beach, some 25 kilometres east of Tobruk.

Since the toppling of Muammar Gaddafi in an uprising in 2011, Libya has become a transit country for people fleeing conflict and poverty across the desert and over the Mediterranean to Europe.

"This latest tragedy is a stark reminder of the deadly risks people are forced to take in search of safety and opportunity. Libya remains a major transit point for migrants and refugees, many of whom face exploitation, abuse, and life-threatening journeys," the IOM said.