A pre-dawn earthquake has sent people running into the streets and caused damage to buildings in Spain's north African enclave Melilla.

The U.S. Geological Survey says the quake measured 6.3 on the Richter scale had its epicenter in the Mediterranean Sea about 77 kilometers (48miles) northwest of Melilla, a small Spanish city surrounded by Morocco and the sea.

Spain's state-owned TVE television says there were no immediate reports of injuries or deaths following the earthquake at 5:22 a.m. (0422 GMT).

Television images showed chunks of concrete on the ground that fell from apartment buildings in Melilla and residents who ran outside in their pajamas following the quake.