An aircraft belonging to the Indonesian Navy plunged into the sea off northern Aceh province on Sunday, killing at least two officers and leaving three others missing. The aircraft carrying seven people on board Sunday en route from Sabang district on the north-western tip of Indonesia to Medan, the north Sumatra capital, when it had engine trouble in unfriendly weather, the state-run 'Antara' news agency reported. Four officers were rescued from the sea but two of them died in hospital and another two are in critical conditions, the report said. Navy rescue teams, joined by fishermen and locals were searching the missing offers, who are feared drowned.