Police probed white powder find

Police in London have investigated reports of a white powder found at Oval station and were treating the alert as a chemical incident, according to a source in the emergency services.

But the Metropolitan Police chief Ian Blair said there was "no evidence" any of the attacks were chemical and said the situation was getting under control.

Passengers who had been on the Tube train were also being tested for chemicals, the source

added.

This is one of four incidents reported in London today.