At least 68 people died and four were missing after a plane crashed into a gorge in Nepal on Sunday, the Nepalese Civil Aviation Authority said, in the country’s deadliest aviation accident in three decades.

In a press release, officials said that Yeti Airlines Flight 691, a twin-engine aircraft carrying 72 people, crashed on approach to a new airport near the resort town of Pokhara. The plane had been arriving from the Nepalese capital of Kathmandu, and had just a 27-minute flight time. 

While the details of what caused the crash remain under investigation, CNN reported that the plane crashed into a deep gorge while landing, falling into a ravine on the edge of a steep cliff at about 10:50 a.m. local time. While rescue workers combed the cliffside and rappelled into the gorge in an effort to locate survivors, Nepalese officials said they were calling off further search efforts until Monday. 

The majority of those onboard were Nepalese, though Civil Aviation officials released a passenger list showing a number of foreigners, including an Argentinian, an Australian, Russians, Koreans, and Indians, among others. 

Bishnu Tiwari, a local resident who went to the wreckage to try and help, told The Associated Press, “The flames were so hot that we couldn’t go near the wreckage. I heard a man crying for help, but because of the flames and smoke we couldn’t help him.”

The accident is Nepal’s deadliest since 1992, when all 167 aboard a Pakistan International Airlines flight were killed when the plane crashed in Kathmandu.