Formerly a Portuguese colony, the region declared itself independent in 1975. In 1976 it was invaded by Indonesia, which annexed and claimed it as the 27th state of Indonesia, a claim which has never been recognized by the United Nations. The region became the scene of bitter fighting and of alleged mass killings by the Indonesian government and military forces. East Timor gained full independence following a referendum in 1999 and a formal declaration by the United Nations in 2002.