Two murals by street artist Banksy have sprung up in central London.
The works, marking the opening of an exhibition by American artist Jean-Michel Basquiat, appeared in a tunnel close to the Barbican Centre.
Banksy described the murals as an "(unofficial) collaboration" in a series of Instagram posts.
Basquiat first rose to fame as a New York City graffiti artist before turning his hand to painting. He died in 1988, aged just 27, from a suspected drug overdose.
Alongside an image on Instagram of the first work - a Ferris wheel - Banksy wrote: "Major new Basquiat show opens at the Barbican - a place that is normally very keen to clean any graffiti from its walls."
The second mural, which bears a likeness to Basquiat's 1982 work Boy and Dog in a Johnnypump, is captioned: "Portrait of Basquiat being welcomed by the Metropolitan Police - an (unofficial) collaboration with the new Basquiat show."
Basquiat: Boom for Real opens at the Barbican Centre on Wednesday.
It has been described by the Barbican as the "first large-scale exhibition in the UK of the work of (the) American artist".