After an inspection on the safety of the Sea-Watch 4 to operate in high seas, Italian authorities placed the ship under an administrative blockade.

The move comes as Italy has been struggling in recent months with daily arrivals of hundreds of migrants from North Africa, a task complicated by security measures imposed under the coronavirus crisis.

Philipp Hahn, head of the Sea-Watch 4 mission, called the justification of the blockade “flimsy” and a “systematic move to prevent civil sea rescue operations in the central Mediterranean”.

The main reason cited was that saving lives did not conform to the vessel’s registration.

Italian officials also said there were too many life jackets on board for a ship which has a sewage system that is unsuitable for the potential number of people rescued.

It is the fifth rescue ship blocked by Italian authorities in as many months.

The Sea-Watch 4 is operated by four humanitarian groups, including Sea-Watch and Doctors Without Borders.

The vessel had rescued 354 people, including 98 unaccompanied minors, families, pregnant women and children.

It waited for days to be assigned a safe port, until survivors were transferred to a ferry for quarantine.

The Sea-Watch 4 crew also spent two weeks in quarantine off Palermo.

“The Sea-Watch 4 is only at sea because of the absence of state-led search and rescue capacity at the world’s deadliest sea border,” Doctors Without Borders said.

It accused Europe of “disregarding its legal and moral duty to save lives”, also citing policies to reinforce the Libyan Coast Guard to block smugglers’ ships from leaving the country, which is not considered a safe haven and where many have reported torture.

So far this year, 379 people trying to reach Europe via Libya have died or gone missing on the perilous Mediterranean Sea crossing, 111 of those in August, the group said.

Migrant rescue groups have long clashed with Italian authorities over their operations.

Italy has come under fire in the past for refusing to allow private vessels carrying migrants to dock.

However, Italy has authorised the arrival of charity ships since it signed a deal with France, Germany and Malta last September.

The deal stipulates participants must voluntarily take in a share of asylum-seekers rescued from overcrowded boats in the Mediterranean.

Over the past five years, at least 19,164 migrants have died in the Mediterranean, the deadliest route for migrants attempting the perilous crossing from North Africa to Italy.