A Turkish oil exploration vessel departed the western Turkish province of Izmir on Friday to begin exploratory work in the eastern Mediterranean. The Piri Reis set sail from Izmir\'s Urla port after a continental shelf agreement was signed between Turkey and northern Cyprus on Wednesday in New York. The move comes in response to exploratory work launched by Greek Cyprus on Monday. Turkey has reacted furiously to exploratory drilling begun by U. S. energy firm Noble on behalf of Greek Cyprus and said it will take \"necessary\" measures if it continues. During his address to the UN General Assembly Thursday Turkish Prime Minister Recep Tayyip Erdogan also criticized the Greek Cypriot administration for its actions. Turkish Energy Minister Taner Yildiz on Thursday said he did not expect any tensions in the eastern Mediterranean in the short term. The island of Cyprus has been divided along ethnic lines since 1974 when Turkey militarily intervened and occupied the northern part of the island in response to a coup by a group of Greek officers. The Greek Cypriots represent the island internationally and are a member of the EU, while the northern part, or the self-claimed Turkish Republic of Northern Cyprus, is only recognized by Turkey. The issue of hydrocarbon exploration in the eastern Mediterranean is highly contentious since no common agreement has been reached by all concerned parties.