Balloon animals have appeared in many carriages on the London underground and no one is quite sure of the identity of the man who put them there.

The balloon animals, like those made by children's entertainers were added to certain tube carriages yesterday on the northern line.

Julia Boggio tweeted: "Man just came onto the tube, put up loads of balloon dogs and then sat down to read a book."

The balloons lasted on the tubes until they were removed by cleaning staff.