Marcus Powell spoke to a local resident who saw a police officer being attacked by the dog in East London.
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Negotiators from London Underground and three unions are meeting at the Euston offices of the concilliation service ACAS.
Clear periods and light winds tonight. Staying warm and muggy. Lows of 17°C.
It took police six days to launch a murder investigation after notorious British criminal John 'Goldfinger' Palmer was shot dead.