Police and fire crews attacked by youths in Londonderry
Fire crews and police have been attacked by youths throwing stones and bottles while tackling a blaze in Londonderry.
They were investigating an arson attack at an electricity substation in Daisyfield Park when they came under attack.
The fire, which caused substantial damage to the substation, was reported at 21:20 BST on Friday.
The damage affected electrical supply to parts of the city for a while.