Italy has grounded a reconnaissance plane used by a German illegal migrant rescue charity, in the first use of tighter regulations for such aircraft, the NGO said.
The National Civil Aviation Authority (ENAC) confirmed on Friday that the Sea-Watch group's Seabird 1 plane had been placed under administrative detention.
It said it acted after being informed by the Italian Coast Guard that the Seabird 1's pilot had failed to notify relevant authorities about an emergency situation at sea.
Sea-Watch called the aircraft's detention, "a new escalation in the Italian government's fight against civilian human rights observation in the Mediterranean".
Italy has temporarily halted dozens of charity rescue vessels, and last year passed a decree allowing similar measures against charity-operated aircraft.
The tighter regulations for rescue vessels and planes, which are used to spot boats in distress, were brought in under Prime Minister Giorgia Meloni, who in the past accused charities of cooperating with traffickers to bring in more illegal migrants.
The government said the crackdown was necessary to ensure better coordination with authorities and avoid abuses. Charities say the measures seriously limit their capacity to operate, putting illegal migrants' lives at risk.
Sea-Watch said it was considering legal options against the grounding of its plane and had deployed another monitoring aircraft to continue its work.
(Reporting by Francesca Piscioneri and Alvise Armellini; Editing by Helen Popper)