With the military coup in 1974 the situation erupted into a major crisis. Turkish military intervention followed and Turkish forces occupied around 38% of the northern part of the island. This invasion caused an exodus of about 160,000 Greek Cypriots to the south. Later voluntary regrouping of population resulted in another 10,000 Greek Cypriots leaving the northern part, and 40,000 Turkish Cypriots moving to the north, which created two homogeneous ethnic zones on the island.