At least 15 migrants jumped into the Mediterranean Sea from an NGO rescue ship and desperately tried to swim to the Italian island of Lampedusa after 19 days adrift. The humanitarian organisation said the situation onboard was “out of control” and “desperate,” and warned the remaining migrants were also threatening to jump into the sea. Footage showed people wearing life vests floating in the sea, some in groups and some individually, with a coast guard vessel hovering nearby and rubber dinghies trying to reach them. The Spanish navy will now escort the remaining 83 migrants aboard the Open Arms rescue ship to Spain after it was denied permission to dock in Italy. The Spanish warship will leave the Spanish port of Rota on Tuesday afternoon and is not expected in the Italian island until Friday. Italy’s hard-line, anti-migrant interior minister Matteo Salvini had refused to allow the boat port access. "The Audaz, which will leave this afternoon at five pm (1500 GMT), will sail for three days to Lampedusa where it will take charge of the people taken in by the Open Arms," the Spanish government said in a statement. After Lampedusa, the boat will then head to Palma, Mallorca. The Open Arms ship has been anchored since Thursday, seeking permission to dock, with the situation increasingly tense. Initially 147 migrants were on onboard but some were evacuated for medical care as were all minors. France, Germany, Romania, Portugal, Spain and Luxemburg had offered to take in the migrants. Madrid initially said last week the Open Arms ship could dock in the southern port of Algeciras but the NGO said the atmosphere on board and the distance meant this would not be possible. The situation has strained relations between Spain and Italy, with Spanish defence minister Margarita Robles saying on Tuesday that Mr Salvini, the Italian interior minister, "has shown he doesn't care about human lives”. "What Salvini is doing in relationship with the Open Arms is a disgrace to humanity as a whole," she also said on Monday. Mr Salvini said the move was the only way to prevent “Italy from becoming Europe's refugee camp again”.