(KRON) — Two United Airlines passengers were sent to the hospital after they were injured during the descent of a San Francisco-bound flight last week, United and the Federal Aviation Administration told NewsNation affiliate KRON.

United Airlines flight 2428 was on its way from Newark, New Jersey, to San Francisco International Airport on Thursday afternoon. At about 12:45 p.m., the Oakland Air Route Traffic Control Center said “another aircraft was in the vicinity” of the United flight.

The plane started its descent to account for the other aircraft, which flew at a lower altitude, United officials told KRON.

United officials said the flight was descending with “the seatbelt sign on.” Despite the visual warning, one customer who was out of their seat belt and another passenger reported being injured. They were sent to the hospital.

The status of the two passengers’ injuries was not shared as of this report. “There was no loss of safe separation,” said the FAA, which is investigating the incident.

“We’re grateful to our crew for their efforts to ensure the safety of our employees and customers,” United said.