A strong earthquake, with a magnitude of 6.1 on the Richter scale, rocked Costa Rica killing at least 32 people and wounding more than 90 others, Red Cross officials said Friday.

Some of these deaths have not yet been confirmed because of the organization's inability to access certain areas, said Carlos Gutierrez, a Red Cross official in capital San Jose.

"There are 14 confirmed deaths, 22 people missing and more than 90 injured," said Red Cross rescue director Guillermo Arroyo.

Another Red Cross official told Deutsche Presse-Agentur dpa that he had received reports of another 18 dead and 10 missing in the town of Cinchona, a rural, mountainous area with dense woodland that was devastated by the quake and is about 60 kilometres north of San Jose.

The quake took place on Thursday at 1:21 pm (1921 GMT) with an epicentre about 35 kilometres north of San Jose. About 10 kilometres west lies the 2,704-metre high Poas Volcano, a popular tourist attraction.

More than 2,200 people had to leave their homes for shelters and other emergency accommodation. Many areas were still impossible to reach by road on Friday.

"In some stretches between Vara Blanca and Cinchona, the road practically disappeared," Pedro Pablo Quiros, president of the Costa Rican Institute of Electricity, told the media after an aerial tour of the area.

Costa Rican television showed large mountain areas destroyed by landslides and several collapsed houses near Vara Blanca and Cinchona.

Hundreds of tourists visit Vara Blanca and Cinchona every day. Residents of the area feared that two Canadians who were hiking when the quake took place may have been killed. At least 300 tourists, many of them foreigners, were cut off in Vara Blanca.

More than 1,200 aftershocks have been recorded since the quake took place.

The National Emergency Commission sounded a red alert in the provinces of San Jose, Alajuela, Heredia and Cartago, where the quake was felt most strongly.

Costa Rican President Oscar Arias was planning an aerial survey of the affected areas and visit some of the quake-hit towns Friday.