A commercial jet was forced to make an emergency landing due to a strange barking noise that could suddenly be heard onboard.

The China Airlines plane was reportedly travelling from Xi'an to Wenzhou on September 1 but its pilots had to urgently land early in Wuhan - some 500 miles away - when the bizarre noise began taking place.

The barking sound - much like that of a dog - can be clearly heard in this seven-second video captured by a stunned Zhang who was onboard Flight CA8524 at the time of the incident.

Zhang said that he first heard the 'barking' during takeoff, although it was relatively quiet at that time.

However, as the Airbus A320 with the registration B-304E climbed up to over 26,000 feet, the sound became particularly loud, and all the passengers could hear it.

The crew was forced to divert from their intended destination and instead land at Wuhan Airport for an emergency inspection. A staff member of China Airlines later claimed the noise did not come from a canine - as many passengers began to suspect - but the plane itself.

It is caused by a mechanical issue that is sometimes experienced by the A320 aircraft and usually does not pose a significant problem.

The staff member assured that 'safety is not a concern and generally, such problems are very rare,' although the risk of temporary faults cannot be entirely ruled out, which is why the crew had to immediately land.

Experienced pilot Chen Jianguo explained that such sounds are often heard during flights and may be related to hydraulic mechanical operations on the aircraft or the operation of the Power Transfer Unit (PTU) on the aircraft.

Chen added that passengers' descriptions of it sounding like a 'dog's bark' are simply a misunderstanding.

As for whether a passenger had transported a pet dog on the plane, he stated that he had never heard of dogs making noise in the cargo hold.

After a thorough inspection, the plane was found to be without issues and it later travelled to its original destination.