Police say they have arrested 367 Extinction Rebellion activists during the first week of London protests as the second gets underway.
On Tuesday, campaigners with painted white prams were expected to descend on Parliament Square for a "slow, silent and sombre walk" to Trafalgar Square to highlight the impact of the climate emergency on children.
It follows a number of disruptive campaigns over the Bank Holiday weekend, which included dozens of protesters occupying the Science Museum over its sponsorship deal with Shell.
The group also blocked Mansell Street with a van and used specially adapted "lock-on" devices to attach themselves to vehicles and bikes and frustrate police attempts to remove them.
A Met Police spokesman said: "Removing these lock-on devices is not impossible, but it takes time. In addition to the caravan blocking Tower Bridge and the blue van blocking the approach on Mansell Street, protesters also lay down on the junction to Tower Bridge.
"We have the tools to remove these lock-ons.
“We see many comments and questions asking why this work can’t be quicker and use more direct tactics.
“While we understand the public’s frustration, we must consider the safety of everyone involved - including our officers. This work is painstaking but we work as quick as we can."
The protests are expected to end this weekend with a "nature rebellion march and after party" starting in St James’ Park on Saturday.
