Italy on Friday urged NATO to help rescue refugees fleeing Libya by sea and called for an inquiry into reports the alliance failed to aid a stricken boat on which dozens were said to have died of dehydration. NATO's mandate in Libya should be changed "to take into consideration the care and rescue of those who are forced to flee by boat, putting their lives at risk because of combat operations," the foreign ministry said in a statement. Italy said it had requested "an internal discussion" on the issue within NATO. Foreign Minister Franco Frattini later said in a television interview that there was "an obligation to protect desperate civilians put on boats by (Libyan leader Moamer) Kadhafi on boats and sent to die in the Mediterranean." Hundreds of refugees -- mainly migrant workers from other parts of Africa who were stranded in Libya when the conflict broke out -- have drowned or died on board rickety boats in desperate crossings from Libya in recent months. Twenty-five refugees are believed to have choked to death in the engine room of a boat intercepted by Italian coast guards on Monday and taken to the island of Lampedusa -- a rocky outcrop in the middle of the Mediterranean. Some of the 370 survivors from another boat that arrived in Lampedusa on Thursday after leaving Libya last Friday said dozens who had died of hunger and thirst were thrown overboard, according to Italian media reports. Italian official sources cited by ANSA said Italy had on Thursday asked for help from a NATO vessel participating in the naval embargo on Libya after being alerted to the stricken refugees by a Cypriot tug that had spotted them. The NATO vessel had been 27 nautical miles away, ANSA reported. The refugees "were left for six days and six nights on the high seas without food or water, forced to look on" as "dozens" died around them," said Mario Testa, a doctor who spent the night treating some of the survivors. Pietro Bartolo, the head of the main clinic on the island, said that around 30 refugees were being treated and were in "a really pitiful state" as some had tried to drink sea water. Many of them were in a delirious state, he added. Italy's chief of defence staff Biagio Abrate said he had contacted the commander of NATO-led operations in Libya, Charles Bouchard, over the incident. NATO said it had been told by Italy on Thursday about a distress call but then confirmed that Italian coast guards had responded to the incident. "Facts of the incident are still emerging and we are working closely with Italian authorities to fully clarify the matter," said NATO spokeswoman Carmen Romero in Brussels, adding that NATO had assisted refugees in the past. NATO gave two examples -- a helicopter rescue of some refugees in March and a NATO ship taking in 100 refugees last month and then delivering them to Tunisia. But alliance ships patrolling the sea off Libya have been severely criticised for failing to come to the rescue of boats that are often badly overcrowded. In the rescue in March, campaigners said a Canadian NATO vessel had not rescued a heavily pregnant woman who was forced to give birth at sea. A NATO spokesman said the alliance had been "monitoring the situation very closely". Then in May Britain's Guardian newspaper reported that a boat carrying 72 refugees had left Tripoli on March 25 but was left drifting for 16 days after European and NATO military units apparently ignored pleas for help. NATO denied that one of its planes had spotted the vessel but ignored it. The refugees who arrived in Italy on Thursday were eventually rescued by Italian coastguards in Libyan waters some 90 nautical miles (167 kilometres, 104 miles) from Lampedusa -- Italy's southernmost point and a major migration hub. European Commissioner for Home affairs Cecilia Malmstroem said "all vessels have an obligation to render assistance to those in distress at sea". She praised Italy's efforts to help the refugees. Charities called for better coordination of rescue efforts. "Humanitarian corridors should be opened as a matter of urgency," Save the Children, which has representatives on Lampedusa, said in a statement. "It is not possible to continue seeing tragedies at sea without doing anything," it added. The UN High Commissioner for Human Rights in Geneva said it would support "full inquiries into any cases where necessary assistance was reportedly not provided by naval units in the vicinity with the ability to conduct rescues."