At least 18 persons were killed after a Saurya Airlines aircraft crashed at Nepal’s Kathmandu airport on Wednesday, the country’s civil aviation authority said.

The aircraft had 19 persons onboard, all employees of the airline. It was bound for Pokhara city for maintenance, Nepal Police said. The pilot, identified as Manish Ratna Shakya, is only survivor of the crash and undergoing medical treatment, the Civil Aviation Authority of Nepal said in a press release.

While 17 of those who died were Nepali, one among them was a Yemeni national who worked as an engineer, reported the BBC.

The aircraft crashed at 11 am during take-off from the Tribhuvan International Airport in the country’s capital, reported The Kathmandu Post.

The accident happened as soon as the plane left the ground, in not even a minute, Tribhuvan International Airport chief Jagannath Niraula told BBC Nepali. “As soon as it took off, it turned right, [when it] should have turned left,” he said.

However, the airport authorities have not been able to confirm the cause of the accident, the BBC reported.