At least 133 bodies had been pulled out of the waters off the Egyptian coast on Friday, three days after a boat carrying hundreds of migrants capsized.

The migrants’ boat capsized on Wednesday, nearly 12 kilometers (7.5 miles) from the Nile Delta port city of Rosetta.

The UNHCR estimates that the boat was packed with some 450 people, while the state news agency MENA said earlier that the number might be as high as 600.

Rescue workers and fishermen said they had rescued at least 169 people, but confusion remained over how many might still be missing.

Health Ministry spokesman Khaled Megahed said 133 bodies had been retrieved from the Mediterranean.

Dozens more are feared dead, Mohammed Sultan, the governor of Beheira province, told The Associated Press.

Egypt has been a traditional route for migrants seeking to reach Europe by sea. The EU border agency, Frontex, recently said more than 12,000 migrants arrived in Italy from Egypt between January and September this year, compared to 7,000 in the same period last year.

Officials said the boat was carrying Egyptian, Sudanese, Eritrean and Somali migrants, and that they believed it was heading for Italy. Four members of the crew were arrested.

The U.N.’s migration watcher says the death toll among people trying to reach Europe by the Mediterranean this year tops 3,500 and is “rapidly approaching” the record level set last year.

International Organization for Migration (IOM) spokesman Joel Millman says its count includes at least 51 people who died following a boat capsizing off Rosetta, Egypt, this week. That figure was expected to rise considerably.

IOM says more than 300,000 migrants and refugees have crossed the Mediterranean this year, mostly arriving in Greece and Italy. More than a million crossed in all of 2015, but the rate of deaths is far higher this year.

IOM has been recalculating its estimates of deaths on the Mediterranean last year, but currently believes that at least 3,675 people died on that sea in 2015.