SAN JOSE (Reuters) - A Costa Rican plane crashed into woodland off a popular tourist beach on Sunday, killing 10 U.S. citizens and two local pilots, the Costa Rican government said.

The accident occurred in the mountainous area off the Punta Islita beach town in the province of Guanacaste, about 230 km (140 miles) west of the capital of San Jose.

Enio Cubillo, director of Costa Rica’s civil aviation agency, said the Cessna 208B Grand Caravan aircraft operated by local company Nature Air had crashed minutes after take-off, but that officials had not yet determined the cause of the crash.

The plane had passed a safety inspection about a month ago and was authorized to fly, Cubillo said. Although strong winds in the morning had forced the pilots to alter their itinerary, they had flown safely to Punto Islita to pick up passengers headed to San Jose.

Nature Air said in a statement that it lamented the accident, without explaining the cause. The flight was part of a special charter service for 20 people, relying on two planes. The first plane, carrying 10 passengers, arrived safely in San Jose at 11:40 a.m. The second, with 10 passengers and two pilots, departed 20 minutes later.

“Regrettably this plane crashed a few minutes after taking off,” Nature Air said.

A video of the crash site obtained from Costa Rica’s Security Ministry shows orange flames consuming a pile of blackened ruins, with plane parts scattered in an area thick with trees.

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Laura Chinchilla, who was president of Costa Rica from 2010 to 2014, said on Twitter that her cousin, one of the pilots, had died in the accident.

A U.S. State Department official confirmed that multiple U.S. citizens had died, but said the agency would not provide further details out of respect for the affected families.

“There are no people alive,” Costa Rica’s Security Minister Gustavo Mata said, adding that autopsies would be needed to confirm the total number and identities of victims because their remains were badly burned.

Punta Islita, on Costa Rica’s Pacific Coast, is popular among North American and European tourists for its pristine beaches and lush landscape.