6.5 magnitude earthquake hits Costa Rica

A strong earthquake with a preliminary magnitude of 6.5 hit Costa Rica last night, shaking buildings and sending people fleeing in panic.

The country's Public Safety Ministry said there were reports of two serious injuries as a result of the quake, but did not provide additional details.

President Luis Guillermo Solis wrote on Twitter that the government was still gathering information.

He also urged people to remain calm and prepare for aftershocks. 

Electricity was knocked out in some areas as power lines and poles fell, but there were no reports of major infrastructure damage from the tremor, which hit in a lightly populated area on the Pacific Coast.

The government reported some rockslides obstructing highways near the epicenter.

The US Geological Survey said the earthquake was centred about 10 miles southeast of the town of Jaco, which is about 60 miles southwest of the capital, San Jose. The quake was at a depth of about 12 miles.

Three people died from heart attacks at the same time as the quake, authorities said, with an investigation attempting to find out if the deaths were linked to the natural disaster.    

Four minutes after the initial earthquake, a magnitude 5.2 aftershock struck.