Pakistan Prime Minister Shehbaz Sharif on Monday said over two dozen Pakistanis were believed to be among 59 people who drowned when a boat carrying migrants to Europe crashed against rocks near the southern Italian coast.

At least 81 people survived Sunday's accident, with 20 hospitalised including one person in intensive care, Italian authorities said.

The wooden boat, which sailed from Turkey, is said to have carried people from Iran and Afghanistan as well.

"The reports of the drowning of over two dozen Pakistanis in a boat tragedy in Italy are deeply concerning and worrisome," Sharif said in a statement, adding, "I have directed the foreign office to ascertain facts as early as possible and take the nation into confidence."

Turkey is part of one of the most-used routes for human smugglers to smuggle migrants into Europe, who at times travel by road, walk for miles and endure being locked in ship containers for days.

Italy is one the main landing points for migrants trying to enter Europe by sea, with many seeking to travel on to northern European nations.

The United Nations Missing Migrants Project has registered more than 17,000 deaths and disappearances in the central Mediterranean since 2014. More than 220 have died or disappeared this year, it estimates. (Reporting by Asif Shahzad, Editing by Raju Gopalakrishnan)