VALLETTA, Malta — A group of migrants desperate not to go back to Libya made it safely to Europe on Thursday after commandeering the oil tanker that rescued them at sea in a dramatic series of events that underlined the contradictions in Europe’s migration policies and could discourage future rescues by commercial ships.

Both Italy and Malta initially refused entry to the Palau-flagged El Hiblu 1. But Maltese armed forces intercepted it overnight after confirming with the captain that he was navigating toward Europe against his will. Special forces boarded it and restored control to the crew.

The 100 migrants, including 15 women and 47 claiming to be minors, left the tanker in a port near the Maltese capital of Valletta; five were handcuffed after being detained on suspicion of being the ringleaders.

Italy’s hard-line interior minister called the hijacking the “the first act of piracy on the high seas with migrants.” But humanitarian groups rejected that label, saying they were victims of “Europe’s inhumane border policy,” citing reports that many migrants have been mistreated, raped and tortured in Libya.

The German humanitarian group Sea-Eye said its rescue ship, the Alan Kurdi, was in the area of the El Hiblu 1 when it heard radio communications between the tanker and a European aircraft monitoring the seas.

The aircraft asked the tanker to respond to two rubber boats, saying that the people on board were “in mortal danger” and that the Libyan coast guard was “out of service.”After the rescue, the captain reported to the aircraft that the migrants “are very upset and do not want to be brought back to Libya.” However, the captain said the Libyan capital of Tripoli was the tanker’s destination.

Sea-Eye spokeswoman Carlotta Weibl said that they don’t have exact information of what happened aboard the El Hiblu 1, but that “we don’t see it as piracy because those people were claiming their right. It was completely illegal for a European plan to send them back to Libya.”

Migrants have long reported that commercial ships either ignore smugglers’ boats in distress, or merely stop to give them water, said Hassiba Hadj-Sahraoui, humanitarian affairs adviser with Doctors Without Borders. Similar incidents could accelerate the trend.

“They are doomed whatever they do,” she said. “This is extremely disturbing for commercial ships. The shipping industry is trying to follow a tenant of international law, which is rescue. But if you are a commercial ship on tight deadlines and you need to deliver goods, it is an impossible situation.”

The International Chamber of Shipping based in London expressed concern about the incident and said it would raise the issue with the U.N. International Maritime Organization.

“If a ship is directed to disembark rescued people in Libya, it creates a potential for conflict between the crew and desperate and frustrated people that might object to being returned,” ICS Secretary-General Guy Platten said in a statement. He added that civilian merchant seafarers “can be severely affected by the traumatic situations they have to face, having complied with their legal and humanitarian obligation to come to the rescue of anyone found in distress at sea.”

Many humanitarian groups have stopped taking part in rescues; in fact only the Alan Kurdi is currently active in the central Mediterranean. Doctors Without Borders suspended their operation in December due to port closures, administrative pressure on Panama to pull its flag, and containment measures meaning that fewer migrants were making it past the Libyan coast guard.

Details of what happened aboard the El Hiblu 1 remain sketchy, but the fact that the migrants made it to European soil makes it unlikely that they would be sent back to Libya.