A nine year old girl needed hospital treatment after a bottle was thrown through the window of a car she was travelling in, showering her with glass.
Abbie Keers was being driven along the A693 in Stanley when she was injured.
Police have described it as a 'mindless act' and are appealing for witnesses.
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Middlesbrough kept their unbeaten re-entry into the Premier League going drawing 0-0 at West Brom.
He has agreed a two-year contract at St. James' Park and becomes the tenth new face in the Magpies' first team squad this summer.
On the back of three consecutive Championship wins, the Magpies sit fourth, poised to move into the automatic promotion places.