Security authorities in eastern Libya freed at least 385 Pakistani migrants who were held in trafficking warehouses in an overnight raid, a migrant rights group said Monday.

Al-Abreen, a group which helps migrants in Libya, said the Pakistani nationals were released early Monday from smugglers' warehouses in the al-Khueir area, roughly 5 miles (8 kilometers) south of the eastern Libyan city of Tobruk. The migrants — among them children — were later transferred to a nearby police headquarters, it said in a post on its official Facebook page.

Esreiwa Salah, an activist with al-Abreen, told The Associated Press the Pakistani migrants arrived in Libya intending to travel to Europe but were detained by smugglers who demanded a ransom for their release. No further details were given.

Several pictures posted on al-Abreen's Facebook page showed dozens of purportedly freed Pakistani migrants sitting outside of a warehouse.

Human traffickers have benefited from the decade of instability, smuggling migrants across borders from six nations, including Egypt, Algeria and Sudan. They then pack desperate migrants seeking a better life in Europe into ill-equipped rubber boats and other vessels for risky voyages on the perilous Central Mediterranean Sea route.

A vessel that departed from Libya carrying an estimated 700 migrants, including about 350 Pakistanis, sank of the Greek coast in June. Only 104 people, including 12 Pakistanis, were rescued.

Pakistan is experiencing an economic crisis that is driving thousands of mostly young men to seek work abroad. Many travel to Libya with the hope of eventually reaching European shores.