Metropolitan Police counter-terrorism officers are investigating an incident where a Ulez camera was blown up using a “low-sophistication improvised explosive device” (IED).
The explosion happened at about 18:45 GMT on Wednesday in Sidcup, south-east London, damaging vehicles and property.
The Met has said it is treating the blast as a “deliberate act”, but not terrorism at this stage.
The remnants of an IED were recovered and have been sent for examination.
No arrests have been made.
In a statement, the force said it believed a Ulez camera which had been installed on Willersley Avenue earlier that day was cut down at about 17:15 GMT.
The Met said an explosion occurred roughly 90 minutes later and police attended the scene alongside London Fire Brigade.
The force added the explosion caused further damage to the camera, as well as to nearby vehicles and a residential property.
Investigators say they are “keeping an open mind as to whether or not there is a connection between the camera being cut down and the planting of the explosive device”, and officers are “carrying out extensive CCTV enquiries in and around the area”.