A meteorologist shows the position of Hurricane Otto on a map, in San Jose, capital of Costa Rica, Nov. 24, 2016. (Xinhua/Kent Gilbert)

SAN JOSE, Nov. 24 (Xinhua)-- Hurricane Otto has increased its strength to Category 2, with winds reaching up to 190km/h as it made landfall on Nicaragua and approached Costa Rica, leading Costa Rica's National Emergencies Commission (CNE) to extend a nationwide alert for the next 48 hours.

Nicaragua's meteorology center, INETER, declared Otto had hit the city of San Juan de Nicaragua, with winds of up to 190 km/h.

INETER director, Marcio Baca, appeared on television to explain that "the hurricane will advance...in parallel to the San Juan river, and will probably reach the town of El Castillo, in the south of the country, but with less intensity."

In Costa Rica, the national emergency office, CNE has opened 16 refuges in which at least 1,335 people have taken shelter in the country's Caribbean, Southern Pacific and central zones.

Tourists stand at Juan Santa Maria International Airport before taking flights in Alajuela, Costa Rica, Nov. 24, 2016. (Xinhua/Kent Gilbert)

Otto's upgrade to a Category 2 was declared as an "unprecedented situation" by CNE president, Ivan Brenes, who told a press conference that people should seek safe shelter and leave rescue operations to specialized teams.

President Luis Guillermo Solís also stated that evacuations in high-risk areas was compulsory, and asked the population to comply with police units in evacuating promptly.

Strong rains caused by Otto's approach have already shut down some the country's main highways, such as route 32, between the capital of San Jose and Limon, and the highway between Zarcero and San Carlos in the north.

Otto killed at least four people in Panama, with several still missing.