Postal workers were greeted with a nasty surprise when a deadly king cobra escaped from its parcel at their office in Indonesia.

The employees were busy sorting packages but fled in terror upon seeing the huge snake crawling out of its cardboard box in Cirebon City, West Java province on June 9.

Castra, officer-in-charge of the courier service, said: 'We immediately contacted the fire and rescue officers to evacuate the venomous snake.

'During the sorting process, the contents of the package came out, and it turned out to be a large king cobra.'

Firefighters quickly caught the 12ft-long snake and sealed it once again inside a box. Cirebon Fire Department head Adam Nuridin said the operation took 23 minutes.

Receipts showed that the wild animal had come from Cilacap City in Central Java, and was headed to Indramayu City in West Java.

Authorities have contacted the sender to retrieve the reptile, which was taken to the Cirebon City Fire Department for safekeeping.

Castra said the incident would serve as a lesson for them to be more careful when handling parcels. No casualties have been reported.

Cobras kill thousands of people each year across Southeast Asia and the Indian sub-continent. They are one of the deadliest snakes alive.