London has seen four small blasts and three tube stations have been evacuated but police have said they are not treating this as a major incident.

Police have requested that members of the public stay where they are for now until they can work out the effect of the blasts.
At least one person is reported to have injured at Warren Street tube station. Reports also say there has been a nail bomb at the station, and that emergency services personnel wearing chemical suits have gone into the station.
Armed police are reported to have cordoned off and to have entered UniversityCollegeHospital in central London, near to Warren Street.
A small blast is reported on a No 26 bus near Columbia Road in east London, travelling from Waterloo to Hackney, whose windows were reported to have blown out; while smoke has been seen coming from Oval station which the emergency services are investigating.
But police have said there is no sign of chemical agents at Oval. Reports suggest a man carrying a rucksack was seen running from the station. Blasts are also reported at ground level at Shepherd鈥檚 Bush tube level.