Pakistan has obtained DNA samples from over 200 families following last week’s sinking of an overcrowded smuggling vessel off Greece that left more than 500 migrants missing, including scores of Pakistanis, authorities said Thursday.

The families had approached authorities, saying they suspected their loved ones were on the boat, spokesperson Mumtaz Zahra Baloch of the Foreign Ministry told a news conference in the capital of Islamabad.

Pakistani police, meanwhile, arrested 10 more suspected traffickers, bringing the number of traffickers detained in the nationwide crackdown to 17, she said. Nearly three dozen other suspects in the case have also been taken into custody.

However, she said the government still cannot verify the number of Pakistanis among the dead or missing from the sinking.

The crackdown followed orders from Prime Minister Shahbaz Sharif for security forces to dismantle human smuggling networks in the country.

The overcrowded fishing trawler capsized last Wednesday with as many as 750 people on board. Only 104 people, including Egyptians, Pakistanis, Syrians and Palestinians, have been rescued and 82 bodies were recovered.

An unspecified number of Afghan nationals were also on the boat.

Pakistanis who tried to make the perilous journey to Europe – hoping for a better life there – had paid the smugglers between $5,000 and $8,000, officials say, adding that some of the detained smugglers allegedly confessed they took money from people who were on the vessel that went down.

According to the Federal Investigation Authority and police, most of the families that provided the DNA samples are from the country’s eastern Punjab province and the Pakistani-administered part of Kashmir, the disputed Himalayan region which is divided between Pakistan and India and claimed by both its entirety.