Some passengers of US-based Delta Air Lines are recovering after a pressurisation issue on a flight from Salt Lake City, Utah, to Portland, Oregon, caused bloody noses and other issues, according to airline and passenger statements.

“We sincerely apologise to our customers for their experience on flight 1203 on Sept. 15,” said a statement from a Delta spokesperson.

“The flight crew followed procedures to return to SLC where our teams on the ground supported our customers with their immediate needs,” the airline said.

A cabin pressure issue on a Delta AIr Lines flight in the US left some passengers with ear and nose bleading. (AP)

Delta technicians fixed the pressurisation issue on the aircraft, the airline said, and the plane was returned to service the following day.

Passenger Jaci Purser said it felt like somebody was stabbing her in the ear.

“I heard some air come out and then it started bubbling. It sounded like my ear was bubbling, my right ear, and I touched my ear, and there was blood coming out,” Purser said.

Purser, who was on a business trip, said her colleagues and other passengers also experienced similar issues.

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“Our ears just started hurting really, really bad. Everybody around us was grabbing their ears, people’s ears started bleeding, people’s noses started bleeding,” she said.

It didn’t take very long for passengers to notice something was wrong on the flight, fellow passenger Caryn Allen said KSL.

“I looked over at my husband, and he had both of his hands over his ears, you know, kind of leaning forward,” Allen said.

“I looked about a row behind me, over on the other side of the aisle, and there was a gentleman that clearly had a very bad bloody nose, and people were trying to help him.”

No serious injuries were reported, but medical personnel identified 10 individuals in need of evaluation or treatment following the flight.

The US Federal Aviation Administration said it will investigate.