An estimated 90 migrants are feared to have drowned off the coast of Libya after a smuggler’s boat capsized early on Friday, leaving three known survivors and 10 bodies washed up on shore, the International Organisation for Migration (IOM) said.

Reuters reported that survivors told aid workers that most of the migrants on board were Pakistanis, who make up a growing number of those attempting the hazardous voyage across the Mediterranean to Italy from North Africa, IOM spokeswoman Olivia Headon said.

“They have given an estimate of 90 people who drowned during the capsize, but we still need to verify the exact number of people who lost their lives during the tragedy,” Headon, speaking from Tunis, told a Geneva news briefing.

“What has been reported to us is that it’s mostly Pakistanis who were on board the boat, but we still need to verify the nationalities and how many from what country,” she said.

According to Reuters,  Headen said ten bodies have washed up on Libyan shores so far, two of them Libyans and the rest Pakistanis.

“I believe the Libyan coastguard is looking for other survivors off the coast,” she added.

Another IOM spokesman, Leonard Doyle, told Reuters Television that the boat was believed to have left shore on Thursday before capsizing early on Friday morning.

More than 600,000 people are believed to have made the journey from Libya to Italy over the past four years.

Prior to Friday’s incident, some 6,624 migrants are believed to have arrived in Europe by sea so far this year and a further 246 have died, according to IOM figures.