The United Nations reported Monday that a distress beacon had been detected from a low-lying Tongan island following Saturday’s massive volcanic eruption, which triggered a tsunami that has killed at least two people. “An active distress beacon had been detected from Mango,” the U.N. Office for the Coordination of Humanitarian Affairs (OCHA) said, adding that the Tongan Maritime Force had been deployed to the island on Sunday. Tonga police have told the New Zealand High Commission that the confirmed death toll stands at two, but with communications in the South Pacific island nation cut, the true extent of casualties is still unclear. “It is too early to fully assess the impact on remote coastal areas of Tongatapu or further afield, including the outer islands, but concern remains about damage in Northern Tongatapu and contamination of drinking water sources and crops, and the resulting need for safe water supplies,” OCHA said …