6.4-magnitude quake jolts Cyprus
The strong and relatively shallow quake that struck at 0107 GMT was centred 48 kilometres (30 miles) west-northwest of the Mediterranean island.
The tremor was felt across the island- Turkish and Greek Cyprus- and around the region with reports from as far away as Turkey, Israel and Lebanon.
It shook buildings around the island Nicosia, 130 km away, and the few people who were awake went out into the streets.
There was, however, a low likelihood of casualties and damage from the quake, the USGS said in a preliminary assessment.
The European-Mediterranean Seismological Centre measured the tremor at 6.5 magnitude at a depth of 51 km.
Cyprus lies in a secondary earthquake-prone zone, but tremors of such magnitude are uncommon.