Drivers on the London Underground (LU) are threatening to strike in protest at attacks by vandals on Tube trains. The drivers' union, Aslef, said trains on the eastern end of the District Line were being pelted with missiles including bricks and stones.
The union said incidents have been increasing, putting the safety of drivers and passengers at risk.
LU said they had targeted crime on that section of the District Line but acknowledged there was "more to do".
An Aslef official said: "Unless something is done and done now, a passenger or one of our members is going to be seriously injured or worse."
London Underground said the safety of passengers and staff was their top priority but that industrial action was not the answer.