The Federal Investigation Agency (FIA) on Sunday arrested four alleged human traffickers linked with the migrant boat tragedy off the coast of Libya.

Earlier this week, at least 16 Pakistanis drowned off the coast of Libya after a smuggler’s boat they were riding capsized. They were among 90 people feared to have drowned in the latest migrant tragedy occurring in the Mediterranean Sea off the coast of Zuwara.

Most of the deceased Pakistani migrants hail from Punjab's districts, including Mandi Bahauddin, Sargodha, Gujrat and Rawalpindi.

Read: The perils of Pakistani migrants

The four suspects were arrested on Sunday after the FIA conducted raids in in Gujranwala, Gujrat and Mandi Bahauddin, the agency's deputy director said.

The raids were conducted as part of a crackdown against those involved in human trafficking, he said.

The International Organisation for Migration (IOM) has pointed out that Pakistanis made up the 13th largest group trying to cross the Mediterranean to Europe last year, with 3,138 of them arriving in Italy in 2017, and no recorded sea deaths.

But they have already climbed to third place this year, with an estimated 240 Pakistanis reaching Italy in January, compared to just nine during the same month last year.