Police have warned shops and businesses in the borough to stay vigilant after a third night of rioting spread across London.

Acting Chief Inspector Hannah Wheeler, of Richmond police, said staff should ring 999 if they were concerned about any incidents or groups of people.

She also urged businesses to ensure their safety shutters and alarms were working and to use them at night to secure their buildings.

It comes after police struggled to cope with the escalating crisis across London last night, as thugs set fire to shops, fought pitched battles with officers and looted stores.

The riots were concentrated around new flashpoints in Croydon, Hackney, Clapham Junction, Newham, Lewishman and Bethnal Green, but the violence also spread to central London where looters smashed the windows of Hugo Boss in Sloane Square.

Chief Insp Wheeler said: “General advice to businesses would be to remain very vigilant and to call police if they feel the slightest concern about an individual, group, incident, location etc.

“If they have safety shutters and alarms please ensure they are in good working order and used correctly at night to secure premises.

“We are providing patrols to the retail park and Richmond town centre to reassure and prevent and detect crime.”

She said Richmond police had provided officers to help in other parts of London, covering shifts where the Met had been stretched.

Firefighters from Richmond and Twickenham also helped put out blazes in neighbouring boroughs, tackling fires at the Priory retail estate, in Colliers Wood, where they stayed until 2am last night.

Crews were also called at 10pm to London Road, in Croydon, where they found flames engulfing shops and flats. They remained there until 6.15am this morning.

Andy Packer, watch manager at Twickenham fire station, said: "We did our best to hold the fire back and managed to stop it spreading the full length of the flats and saved several properties."

Richmond police said the riots had stretched their resources but they were working to mitigate any effects. Safer neighbourhood teams have started 12 hour shifts to increase their presence in areas including retail parks and town centres.

Chief Insp Wheeler said she was liaising with Richmond Chamber of Commerce and officers were speaking with their communities.