The BBC has this news report saying that:

Minor explosions using detonators only have sparked the evacuation of three Tube stations and the closure of three lines, a BBC correspondent has said.
Police cordoned off large areas around Warren Street, Oval and Shepherd’s Bush Tube stations.
A route 26 bus in Hackney Road in Bethnal Green had its windows blown out by a blast. There were no injuries.

[…]

One person was injured at Warren Street, although the person’s condition is unknown.