“Twenty people are reported missing in the Mediterranean after a shipwreck on September 1st,” UN official Chiara Cardoletti said on X.

“The seven survivors, taken in by our team on Lampedusa, are in a critical condition,” she said, adding that several of them had lost loved ones in the disaster.

Italy’s coast guard, which said it had rescued the survivors on Wednesday morning, said 21 people were missing.

It said the vessel, found 20 kilometres off Lampedusa, “was drifting half-submerged in the water and on the point of sinking, with seven migrants on board, all of them men of Syrian nationality”.

Coast guard footage showed the men in a small vessel completely filled with water, sliding to the rescue boats on inflated slides.

“The rescued migrants said that they had left Libya on September 1st with 28 people on board, three of them minors, 21 of whom had fallen in the water because of the bad weather conditions,” coast guard said in a statement.

It was continuing to search for those missing, with an aircraft helping with the operation.

News of the latest sinking came on the same day that Italian authorities decided to stop a rescue ship run by the Sea Watch group, saying it had not waited for Libyan authorities to approve a rescue operation.

Sea-Watch 5 arrived in the Italian port of Civitavecchia, Lazio, on Wednesday, carrying 289 people it had rescued. It will now have to wait 20 days before being able to leave port again.

READ ALSO: Charity warns Italy’s ban on migrant rescue planes risks lives

Many charity ships have been detained, sometimes repeatedly, for breaking the law, though those detentions are sometimes overturned by the courts.

In 2023, more than 3,000 migrants were reported missing after having attempted the perilous Mediterranean crossing from North Africa, according to the International Organization for Migration (IOM).

Interior ministry figures suggest those numbers have fallen sharply since the beginning of the year.

According to them, 43,061 migrants have arrived in Italy since the start of the year, compared to 115,177 over the same period last year.

Since Giorgia Meloni’s right-wing coalition government came to power in October 2022, it has sought to stem the arrival of migrant boats into Italy from North Africa.

Italian law requires that NGOs head “without delay” to a port immediately after a rescue is completed, thus preventing them from carrying out several in a row.

The NGOs argue that it violates maritime law, which requires any ship to come to the aid of a boat in distress.

But failure to comply is punished with a fine of up to 10,000 euros, and the temporary or definitive seizure of the vessel.