Street artist Banksy's murals left across Detroit and Bethlehem are to be auctioned in Los Angeles on 30 September.

The murals to be auctioned include one depicting a donkey whose travel documents are being studied by a soldier. The mural was left on a wall dividing the West Bank and Israel in 2007.

The second mural on auction was left on the wall of a Detroit factory in 2010. The mural shows a young child holding a bucket of red paint with a writing on a wall saying, "I remember when all this was trees."

Though there is no confirmed proof that the murals are in fact a product of Banksy, they are predicted to generate a total of $1mn (638,000), reported BBC News.

The mural detached from the West Bank and Israel is believed to be, "the largest and most significant intact Banksy mural in existence from his visit to Israel," according to auction house Julien.

The auction is planned to take place in Los Angeles on 30 September.