Just Stop Oil has blockaded the area around Mansion House tube station during rush hour in its latest protest action.
The eco group said 31 of its activists began blocking Cannon St, Queen Victoria St and Garlick Hill from 9am.
It said some have glued themselves onto the tarmac and eight supporters have locked on to each other.
City of London Police said: “We are aware of a group of protestors blocking Cannon Street, junction with Queen Victoria Street.
“Our officers are in attendance and are working to minimise disruption. Thank you for your cooperation”.
