Italian navy ship Vega recovered 45 bodies near a sinking rubber vessel close to Libya on Friday.

The rescuers also managed to save 135 people and reported ongoing search efforts. There was no immediate information on the total number of passengers on board the boat.

Officials said 17 different rescue operations were carried out in the Mediterranean Sea on Friday, allowing workers to bring 2,000 people to safety.

On Thursday, rescue teams saved some 4,000 people in 22 deployments. The authorities also retrieved 15 bodies after a refugee boat capsized, according to a source in Italian interior ministry, but some survivors have claimed the death count was actually closer to 200 people.

Summer spike as new normal

Warm weather and calm seas have prompted many thousands of migrants to attempt to reach Italy by sailing from Libya in recent days. Many of them cannot swim and have no life jackets, with people smugglers sending them off on flimsy and overcrowded vessels.

Rescuers picked up a total of 14,000 people this week, according to the UN and coastguard representatives.

"It's obvious that no matter the great effort made by rescuers, when the numbers are as high as we're seeing this week, it's very risky," said Federico Fossi, a spokesman for the United Nations High Commissioner for Refugees (UNHCR) in Rome.

"But in terms of numbers, it's the third year that this is 'normal'," Fossi said. "It's the beginning of the high season, and we're still at slightly fewer arrivals compared with the same period last year."

Survivor recounts boat's capsize

The Italian navy also published a video of a fishing trawler capsizing on Wednesday, reportedly with 650 people aboard.

Survivor Mohammed Ali told the AP news agency that the smugglers ignored the captain's warnings that the ship was overloaded.

"The captain said to him, 'It's too many people, stop bringing more people," said Ali. "They didn't listen to him."

The 28-year-old Sudanese man said he paid 1,500 euros ($1,667) for the trip. According to Ali, the wooden ship started its voyage from the Libyan coast early on Wednesday. It soon started rocking left and right "because the passengers were moving too much."

After the refugees spotted the rescue ship, many of the passengers below deck rushed up, causing the vessel to capsize.

"They wanted to be saved," Ali said. "When they came up, the ship started to flip."

Ali found himself under the overturned boat, but managed to reach the surface and hold on until the rescuers found him.

"I can't swim actually. After the boat sank, I tried to swim," Ali said. "My friends - one of them drowned. I saw him close to me. You couldn't do anything. I can't swim. If I had tried to save him, I would have drowned with him."