The Tyre Extinguishers group - which has around 300 followers on social media - said they have taken "emergency action" to let down the tyres on vehicles in Meanwood and across the rest of Leeds.
The group claims to have deflated the tyres on 85 SUVs across Leeds overnight.
It describes itself as "ordinary people terrified by the complete unwillingness of governments, corporations and individuals to combat the climate and nature crisis".
They say they have carried out the act in many cities across the world, including London, in recent months.
"We have acted for our family and friends, children at school now and all the many people we will never meet who are already suffering and dying from the consequences of this inaction", the group said in a statement released last night.
"The threat to all of our lives is dire and irreversible. Yet we have so many solutions at our fingertips, just waiting to be deployed, for the benefit of all.
"SUVs however - even electric ones - are simply not compatible with a liveable future.
"We must all ask ourselves what we can do in this time, together, to create the change needed to avoid the worst impacts."
The group says the tyres have been deflated using the valves, with "no irreversible damage".
No cars with blue badges or traders' vehicles have been affected according to the group’s statement.