Clerks at a South African post office fled for safety when they emptied a mail bag and a white python came slithering out.

The one metre-long non-venomous snake was one of four sent this week in an express parcel that arrived at the Sabie Post Office, about 300 km northeast (185 miles) of Johannesburg, postal officials said.

Once the python hit the floor, sorting room employees were out the door, Sabie Branch Manager Mthobisi Duba said.

"This was the most traumatic experience ever in the post office," Duba said in a statement.

An official from the local parks board collected the white python and the three other smaller snakes still in the parcel. The parks board is taking care of the reptiles.

The receiver of the parcel was charged with the illegal transport of animals, South Africa's post service said.