(ECNS) – Hainan Airlines passenger flight HU7148 encountered strong turbulence on its way from Chengdu to Beijing on Tuesday afternoon, injuring at least 28 passengers and crew members, according to Chinese media reports.

The Beijing News cited a passenger surnamed Zhang onboard the A330-200 as saying that most of those injured did not have their seat belts fastened when the turbulence caught everyone by surprise. Most of the victims had injuries to their feet or heads.

The turbulence lasted several minutes, and ambulances were waiting at Beijing Capital International Airport when the plane safely landed there, passengers said.

The jet met with the turbulence at 4,200 meters above sea level on its descent and landed at Beijing airport at 2:17 pm on Tuesday, the airline company and media reports say.

The injured, less a few who only suffered slight injuries, were immediately hospitalized. The exact cause of the turbulence is still being investigated.