An airport employee has died after being sucked into a passenger plane engine in Texas.

The worker was "ingested" into the engine of a Delta plane that was taxiing towards its gate with one engine turned on, officials said.

The worker's employers say an initial investigation shows the incident was unrelated to safety procedures, but it is not yet clear how it happened.

An investigation is also being carried out by a government agency.

The National Transportation Safety Board said it had been in contact with Delta Air Lines and was "in the information gathering process at this point."

The plane, an Airbus A319, arrived at San Antonio on Friday night from Los Angeles International Airport.

Officials have not yet named the employee of Unifi Aviation, which Delta Air Lines contracts for ground crew operations,

"From our initial investigation, this incident was unrelated to Unifi's operational processes, safety procedures and policies," the company said.

A Delta spokesperson said the airline was "heartbroken" to grieve the loss of an "aviation family member's life".

"Our hearts and full support are with their family, friends and loved ones during this difficult time."

The airline also told local broadcaster Kens 5 that it was working with authorities "as they begin their investigation".

On Wednesday, regional airline Piedmont was fined $15,625 (£12,285) by the Occupational Safety and Health Administration (OSHA) for the death of a ground crew worker six-months earlier in a similar incident in Alabama.

"Proper training and enforcement of safety procedures could have prevented this tragedy," OSHA said.