A boat carrying 35 people has capsized off the Libyan coast, the UN migration agency has said.

The incident took place on Friday off the western Libyan city of Sabratha, a major launching point for the mainly African people making the dangerous voyage across the Mediterranean, said the International Organization for Migration.

The IOM said six bodies were pulled out of the water while 29 others were missing, presumed dead. It was not immediately clear what caused the wooden boat to capsize.

The tragedy is the latest to involve people departing from north Africa to seek a better life in Europe. This past week alone, at least 53 have been reported dead or presumed dead in Libya, according to the IOM.

“Dedicated search and rescue capacity and a safe disembarkation mechanism are urgently needed to prevent further deaths and suffering,” the IOM said.

Investigators commissioned by the UN’s top human rights body found evidence of possible crimes against humanity committed in Libya against people detained in government-run detention centers and at the hands of human traffickers.

Earlier this month, more than 90 people in an overcrowded boat drowned in the Mediterranean Sea days after they left Libya, according to the Doctors Without Borders aid group.

People regularly try to cross the Mediterranean from Libya in a desperate attempt to reach European shores. The country has emerged as the dominant transit point for those fleeing war and poverty in Africa and the Middle East.

Human traffickers in recent years have benefited from the chaos in Libya, smuggling people in across the oil-rich country’s lengthy borders with six nations. Their “customers” are then typically packed into ill-equipped rubber boats and set off on risky sea voyages.

At least 476 people died along the central Mediterranean route between 1 January and 11 April, according to the IOM.