San Jose - A strong earthquake, with a magnitude of 6.1 on the Richter Scale, shook Costa Rica on Thursday, but there were no immediate reports of casualties or damage to property.

According to the US Geological Survey, the earthquake was centred about 35 kilometres underground and 35 kilometres north of Costa Rican capital San Jose, where the tremor was strongly felt.

The earthquake took place at 1:21 pm (1921 GMT) and caused widespread panic in San Jose, with residents rushing out of shaking buildings. (dpa)