Malta has been accused of letting 12 people die of thirst while stranded on a migrant boat in the Mediterranean.
Alarm Phone said on Thursday that 55 people have been returned to Libya. The migrants were picked up by a merchant vessel and returned to Tripoli.
But "12 people died of thirst or drowned because Malta failed to rescue," it said.
"Survivors were illegally pushed back to Libya where they will again suffer from torture and rape," Alarm Phone continued.
Last week, Malta followed in Italy's footsteps and closed all ports to migrant vessels. The government says all resources are dedicated towards containing the spread of Covid-19.
Foreign Affairs Minister Evarist Bartolo has called on the European Union to launch a humanitarian mission in Libya to incentivise migrants to stay there, rather then face the dangers of a sea crossing. He said Libya should be given aid to provide migrants with the necessary living and medical facilities.
On Wednesday, the Maltese bishops wrote to the Vatican urging it to call on the EU to share the burden of migration.
The migrants who were returned to Libya were from Eritrea and Sudan. They disembarked in Tripoli after spending hours on a coast guard vessel and were later detained by local authorities, the UN migration agency said.
The UN mission in Libya, meanwhile, voiced concern about an escalation of fighting between rival forces over Tripoli in recent days, and the release of over 400 jail inmates in a western town recently taken by Tripoli-allied militias.
The migrants were handed over to Libya's coast guard after being rescued Tuesday night by a commercial ship in Maltese territorial waters, the International Organization for Migration said.
A spokesperson for the IOM said there were eight women and three children among the rescued migrants.
"We reiterate that people rescued at sea should not be returned to unsafe ports," the UN migration agency said. "An alternative to disembarkation in Libya must be found urgently."
The Maltese government said in a statement Wednesday that its Rescue and Coordination Center coordinated the rescue of the migrants who entered Malta's waters after a few days in Libyan waters.
It said the Maltese military carried out flights to pinpoint where the boat was located, and called nearby vessels to assist. The statement said the migrants were assisted by a commercial vessel. Later, a Libyan fishing vessel took the migrants on board, it said.
Malta said the European Union was aware of the boat as it was located in Libya's waters. The EU flew its aircraft over the area but did not send any vessels to pick up the migrants, it said.
Doctors write to Prime Minister
In a letter sent to the government through the Daphne Caruana Galizia Foundation, some 250 healthcare professionals and students called on Prime Minister Robert Abela to reconsider his stance on assisting lives in danger at sea.
"The Armed Forces of Malta are being prevented from rescuing any boats in distress within Malta's SAR. This comes as a shock to us and raises the question: must our COVID-19 response come at the expense of human rights?"
"The Hippocratic oath clearly states: I will remember that I remain a member of society, with special obligations to all my fellow human beings, those sound of mind and body as well as the infirm," they noted.
"In times of a pandemic, many otherwise normal actions come with a risk. Some of these risks we have taken. For example, not enforcing a full public lockdown and allowing the hunting season to commence. While rescuing people in distress at sea and allowing them to disembark in Malta is not totally risk-free, it does not justify violating human rights and there are steps that can be taken to mitigate risk. We acknowledge that the current COVID-19 situation in Malta is serious. However, allowing people to die in the name of public health is contradictory and utterly nonsensical," they said.
"We cannot abandon our moral and ethical responsibilities and the state likewise cannot abandon its positive obligation to protect the right to life. We ask the prime minister to reconsider his stance and to come to the aid of those whose lives are at risk at sea. If we allow the government to pay for public health with people's lives, we will have failed in our obligations as citizens, healthcare workers, and as a nation."