Hundreds of people, including from Pakistan, are thought to have died when the vessel capsized and sank in one of Europe’s deadliest shipping disasters in recent years.

The Pakistani government has ordered a high-level inquiry to investigate the human trafficking network thought to be involved, a statement from Prime Minister Shehbaz Sharif’s office said.

“My thoughts and prayers are with the bereaved families who lost their loved ones,” Sharif added.

At least 21 of those who died came from the Kotli district in Pakistan’s part of the Himalayan Kashmir region, police official Riaz Mughal said. Two of the 12 Pakistanis who survived the sinking also came from the same town.

“We have already arrested 10 suspects who are part of a human trafficking network that sent these people to Europe,” senior regional police officer Tahir Mahmood Qureshi told Reuters. “We are hunting for more suspects.”

Some of them had already been traced and the police were conducting raids to arrest them, while others had gone into hiding, he added.

A further four people were arrested in the eastern Punjab province, a senior official at Pakistan’s Federal Investigation Agency (FIA) said.

Witness accounts suggest that between 400 and 750 people were packed on to the fishing boat that sank about 50 miles (80 km) from the southern Greek town of Pylos.

Greek authorities have said 104 survivors and 78 bodies of the dead were brought ashore in the immediate aftermath. Hopes were fading of finding any more people alive.

Most of the people on board the capsized boat were from Egypt, Syria and Pakistan, Greek government officials have said.

By Abu Arqam Naqash

(Writing by Asif Shahzad; additional reporting by Gibran Peshimam; Editing by Emma Rumney and Angus MacSwan)