The UN refugee agency said Friday it feared that up to 1,200 people fleeing Libya have died in the Mediterranean Sea so far, as it found evidence that a military vessel refused to rescue one boat. \"There are about 12,000 people who have arrived in Italy or Malta and we believe that as many as 1,200 people are dead or have gone missing,\" said Melissa Fleming, a spokeswoman for the UN High Commissioner for Refugees. A migrant told the UNHCR that unidentified military vessels off the Libyan coast refused or failed to pick up a boat carrying 72 people, most of whom subsequently died of exhaustion, thirst or starvation in late March or early April. Fleming told AFP that the survivor\'s harrowing account obtained after a long interview on Thursday was \"compelling and credible\". \"At Shousha refugee camp run by UNHCR in Tunisia we met with three of the survivors. They were Ethiopian men, they said they were among only nine survivors from the boat that left Tripoli on 25 March carrying 72 people,\" she told journalists. The 12-metre (40-foot) craft heading for Italy was packed with \"barely any standing room\" and drifted for more than two weeks after it ran out of fuel, water and food. \"The refugee that we interviewed said that military vessels twice passed their boat without stopping and then a military helicopter dropped food and water onto the boat at some point during the journey,\" Fleming added. \"The first boat refused their request to board, the second only took photos,\" according to the refugee. The man was unable to identify where the vessels came from, Fleming said. \"According to the refugee, when water ran out people drank sea water and their own urine. They resorted to eating toothpaste,\" Fleming said. \"One by one people started to die\" until the boat reached a beach in Libya, he said. The account followed a report in the British newspaper The Guardian this week claiming that it was likely one of the ships was the French aircraft carrier Charles De Gaulle, which is helping to enforce a no-fly zone over Libya. The UNHCR is planning to interview the other survivors. \"We don\'t have any more information at this time,\" Fleming said. \"We have been in talks with NATO and we\'ve just issued a general call to remind boats and countries that people are taking this route\" on unseaworthy and overcrowded craft, she added.