Twenty men made off after scaling a fence at Lindholme prison, near Thorne, South Yorkshire, at about 2020 BST on Sunday.

None have been found despite a search by up to 20 officers with cars, a helicopter, dogs and cars, police said.

Although they are not believed to be dangerous the public have been warned not to approach the men, last seen in in the Blackstone and Dunsville areas heading towards the A614.

The men are asylum seekers from Iraq, Kosovo, the Ukraine, Macedonia and India and were understood to have been waiting for their applications to be processed.

Anyone who spots them should contact South Yorkshire Police on 0114 220 2020.