A powerful earthquake measuring 6.2 on the Richter scale struck north central Costa Rica on Thursday, killing two girls and causing widespread damage, EFE news agency reported on Friday.
According to authorities, two children were killed after a landslide following the quake buried thier house in the town of Fraijanes de Alajuela, about 50 km west of San Jose, in Alajuela province.
The epicentre of the quake was near Poas volcano, one of Costa Rica's main tourist attractions, in Alajuela province, about 60 km northwest of the capital San Jose.
According to Juan Segura, head of Costa Rica's Ovisicori Seismology Institute, the quake struck at 1:21 p.m. and was felt across the country.
Witnesses said they had not felt such a strong tremor in the past 30 years.
The greatest impact from the quake and its aftershocks - 200 so far - was felt in the towns of San Pedro de Poas and Vara Blanca, with homes flattened, roads rendered impassable and some neighbourhoods cut off.
Buildings were also damaged in San Jose and the city of Alajuela, where police evacuated offices as a precaution.
National Emergency Commission chairman Daniel Gallardo declared a red alert in the central provinces of Alajuela, San Jose, Cartago and Heredia.
Thursday's earthquake was the result of a series of mini-temblors around Poas volcano, Segura said, adding that there was no sign of volcanic activity.
Authorities in neighbouring Nicaragua said the quake was felt in parts of their territory, but did not cause any damage or injuries.
Costa Rica registered more than 4,700 earthquakes in 2008, of which around 60 were felt by the population, according to the country's Seismology observatory.