The bodies of 148 people had been pulled from the waters off the Egyptian coast by Friday, three days after a boat carrying hundreds of migrants capsized in the Mediterranean while attempting to head to Europe.

Wahdan el-Sayyed, the spokesman of the Nile Delta province of Beheira, provided the latest figures and told The Associated Press that the search operation was ongoing. Dozens more are feared dead, Mohammed Sultan, the governor of Beheira, said earlier. Many of them are believed to be children and women who were unable to swim away when the boat sank.

An AP reporter near the Nile Delta city of Rosetta saw between 20 to 30 bodies brought in by fishing boats early Friday morning and delivered to a group of waiting ambulances at the coast guard pier. Pictures posted on social networking sites showed dozens of bodies lined up in black plastic bags, and others floating near wooden fishing boats.

Authorities have struggled to give accurate figures for the number of people on board the capsized vessel. The boat was located nearly 7.5 miles from the Nile Delta port city of Rosetta, when it sank. It had waited at sea for many hours — perhaps days — for smaller wooden boats carrying migrants to arrive from different points along the Egyptian coastline.

Survivors said that overcrowding caused the boat to capsize.

The head of the local council in the area, Ali Abdel-Sattar, said that the currents have carried the bodies of the victims many kilometers away from the site of the sinking. "Today, four bodies, including two Egyptian children, were found 20 kilometers to the east," he told the AP.

He added that many of the migrants are believed to have been "stored in the bottom of the boat, in the fridge."

"Those are the ones who drowned first, most probably stuck, and their bodies might not be retrieved anytime soon," he said, adding, "those we found are the ones liberated from the boat. I believe many are stuck and now laying in the bottom of the sea." He said the boat may now have sunk to 16 yards below sea level.

The UNHCR estimated 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.

"UNHCR is deeply saddened by the loss of life after yet another boat capsized in the Mediterranean," the U.N. refugee agency said in a statement. Of the 150 people rescued, UNHCR said that the majority are Egyptians, while the others are Sudanese and other nationalities, including Somalians and Eritreans.

On Thursday, four people described as members of the vessel's crew were arrested over charges of human trafficking and manslaughter.

Egypt has been a traditional route for migrants travelling to Europe by sea. However, UNHCR said that since 2014 there has been a steady increase in the number of people intercepted while trying to leave.

Over 4,600 people of different nationalities were arrested this year, UNCHR said, a 28-percent increase compared to last year.

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.

At a small pier called el-Borg, hundreds of families had gathered Friday, hoping to identify the bodies of their loved ones. Women screamed and relatives pushed and shoved while swarming the ambulances heading to the hospital.

Fishermen said that they had difficulty collecting the badly decomposed bodies, with one saying, "we didn't know how to pull them out."

The intense smell of decay filled the air and many covered their faces with masks.

Survivors and relatives told the AP earlier that the boat sank around 5:30 a.m. on Wednesday, and that it took coast guards around six hours to come to the rescue. Fishing boats in the vicinity were the first to provide help.

At Rosetta General Hospital, Abdel Raouf Mustafa Abdel-Garih, the father of a still-missing migrant, spoke late Thursday about his son: "a young man, who was 23 years old, he left on the basis that he would go work there, and the boat never came back, and we don't know where he's headed now. We've been here for three days now."

Many of the survivors were briefly detained by police. Some of those rescued were taken to hospitals, where they lay handcuffed to beds and under police guard.

After his release, survivor Ahmed Darwish said, "my advice is that no one should undertake this risk, and especially anyone who saw these things, they will never do it again."

The Egyptian news portal, Al-Youm al-Sabei, published interviews with several survivors who recounted seeing entire families taking the risky journey after having been "stored" for several days in chicken farms by the traffickers to evade police. Some of the interviewees said the traffickers asked for $6250 per family, to be given on arrival in Italy. They said the traffickers asked the migrants to tell the Italian authorities that they are Syrian refugees.

The International Organization for Migration has said that this year over 3,500 have died while attempting to cross the Mediterranean to Europe, with this number "rapidly approaching" the record death toll set last year. It said that 300,000 have crossed the Mediterranean this year, mostly landing in Greece and Italy. More than a million crossed in all of 2015, but the rate of deaths is far higher this year.

Those who chose to risk the dangerous journey are often fleeing war and poverty in the Middle East and elsewhere..