'Mindless' vandals smashed a police car windscreen as officers helped a pensioner who had been injured in a fall.
The officers discovered the vandalism when they returned to their car after handing the care of the elderly man over to paramedics, in Old Trafford on Friday 10 March, night.
The vehicle then had to be taken off the road preventing the officers from attending any other emergency.
In a post on social media they hit out at the "mindless criminal damage" adding: "I hope one day, if your loved one needs our help having collapsed, someone else hasn’t done something similar and we can’t respond as we should."
In message on Facebook Trafford Police expressed their anger and said: "Officers from Trafford were dealing with an elderly male at Empress Court, Old Trafford who had fallen and couldn’t get up.
"When they handed the care of the male to our colleagues from the ambulance service, returning to their car they discovered some kind soul had smashed the windscreen.
"This prevented the officers attending other incidents where members of the public also needed their help until the vehicle was recovered.
"This mindless criminal damage stop us helping victims of domestic violence, prevents us from searching for missing children or any of the hundreds of incidents involving the most vulnerable people in our community who need our help.
"I hope one day, if your loved one needs our help having collapsed, someone else hasn’t done something similar and we can’t respond as we should."