Polar bear appears to stroll onto packed Tube train in front of startled commuters

It's been pretty chilly lately. But surely not this cold. A polar bear appears to have turned up in London. The 8ft-long creature was spotted in Hampstead Heath, the London Underground and the South Bank.

The animated animal was constructed by 19 prop specialists, who spent two months designing and building the replica bear.

Two puppeteers from the West End show War Horse controlled the movements of the bear, which was built to promote Sky Atlantic's new "Arctic-noir" series Fortitude, from inside.