Updated 4.40pm

Twenty-seven unaccompanied minors aboard a Spanish charity ship will be evacuated by the Italian coast guard, the NGO responsible for the ship has said.

"They will be evacuated by coastguard Lampedusa," Proactive Open Arms tweeted after far-right Interior Minister Matteo Salvini reluctantly authorised the disembarkation.

Mr Salvini wrote in a letter to Prime Minister Giuseppe Conte that he could authorise the "alleged" minors to leave the Open Arms ship despite such a move being "divergent to my orientation."

106 adults and two accompanied minors aboard the Open Arms must remain on the ship. 

The decision came hours after the ship's captain warned of an "explosive" situation on board the vessel anchored within swimming distance of Italy's Lampedusa island but forbidden to approach.

Italy has evacuated a handful of people from the Open Arms ship for medical treatment but far-right Interior Minister Matteo Salvini refuses to allow the vessel to dock despite other European countries agreeing to take in the people on board.

The captain of the ship operated by Proactiva Open Arms, Marc Reig, said the migrants, rescued after leaving chaos-stricken Libya, were "broken psychologically".

"Every second that passes, the bomb ticks a second closer. Either someone cuts the red cable and defuses this bomb now, or the Open Arms will explode," he told Spain's TVE television.

Every second that passes, the bomb ticks a second closer. Either someone cuts the red cable and defuses this bomb now, or the Open Arms will explode- Ship's master

"This is inhuman. We're close to land and people could swim there. They want to throw themselves in the water. It's untenable. They can't take it anymore."

The mainly African migrants aboard Open Arms have been plucked from boats in the Mediterranean this month, with weather conditions encouraging more departures from Libya.

In an interview with the Times of Malta, a rescued Ethiopian, Mohammed, recounted the horrors of his attempted crossing. 

"There were 15 of us in the boat and I'm the only survivor," the 38-year-old told the newspaper from his hospital bed. 

Having fled Ethiopia 15 years ago, Mohammed made his way first to Eritrea and then Sudan. 

In Zawiya, west of Tripoli, he paid a smuggler $700 for passage to Europe and was offered a place on a small inflatable dinghy, alongside two Ghanians, two other Ethiopians and 10 Somalians. 

First the fuel ran out, then the food, and then the water. 

"We saw a lot of boats. We cried help and signalled to them, but they didn't stop. A helicopter also flew over and then went away," Mohammed recounted.

He said he could not recall when the Maltese armed forces, alerted to the boat by a plane belonging to Europe's Frontex border agency, arrived and he was transported by helicopter to a hospital in Malta. 

'Taking the world for a ride ' 

Mr Salvini, who is also deputy prime minister, insisted Friday he would "not give in" and accused NGOs such as Open Arms of "taking the world for a ride".

The Open Arms "has been dancing around the Mediterranean Sea for days with the sole aim of picking up as many people as possible to, as always, bring them only to Italy," he said in a statement.

"In all this time it could have gone to a Spanish port and back three times! These NGOs are just interested in scoring political points at the expense of the migrants and our country," Mr Salvini said. 

Prime Minister Giuseppe Conte said Thursday "France, Germany, Romania, Portugal, Spain and Luxembourg have told me that they are ready to welcome the migrants".

But late Friday, sources close to Italy's interior ministry said no clear plan has been forthcoming.

"No European country has taken formal steps to take the migrants on board," one source said.

The UN refugee agency regretted the European offer had been so long in coming.

"People cannot be left at sea for days on end. Predictable, regional and fair approach urgently needed so no rescued person is again left at sea for so long," the UNHCR tweeted. 

'Conscience' 

In Brussels, spokeswoman Vanessa Mock said the European Commission welcomed the willingness of member states to help relocate the migrants.

The Commission is ready to help "once a solution has been found for the disembarkation of the persons rescued at sea. The situation where persons are stranded at sea for days and weeks on end is untenable."

The fate of the migrants aboard the Open Arms vessel is at the centre of a political crisis in Italy.

Earlier this month, Mr Salvini signed a decree banning the Open Arms from Italian waters, saying it was to protect public order. 

But Proactiva appealed to the administrative court which on Wednesday suspended his decree.

Mr Salvini then signed a new one blocking the ship, but in a demonstration of his diminished power, Italy's Defence Minister Elisabetta Trenta blocked it as an act of "conscience".

Trenta's Spanish counterpart Margarita Robles said Friday this showed Mr Salvini had been "discredited by his own government."

Another rescue ship, the Ocean Viking, operated by SOS Mediterranee and Doctors without Borders (MSF), is also looking for a port to dock with more than 350 migrants on board.