(Reuters) - An earthquake measuring 6.0 magnitude struck off northwest Colombia on Tuesday, the U.S. Geological Survey (USGS) said. There were no immediate reports of damage or casualties.

The USGS said the quake was centered 129 km (about 66 miles) north northwest of Medellin. It was 72 km (45 miles) deep.

(Writing by Nick Macfie; Editing by Michael Perry)