Chief Constable Ian Hopkins has slammed people who are treating the coronavirus crisis like a 'holiday'.
He spoke out after seeing people leaving a supermarket in Gorton with a shopping trolley full of booze and charcoal for a BBQ.
His officers had also had to deal with people lighting bar-be-cues in parks, taking advantage of the sunny weather despite the lockdown.
"That's not acceptable," he said.
People are being told to stay at home and only leave to shop for 'basic necessities', for medical reasons, to care for someone or to go to work where 'absolutely necessary'.
Gatherings of more than two people are banned. New legislation being introduced will give police powers to dish out £30 fines to those who ignore the rules.
The chief constable said that when he went out on patrol on Gorton on Wednesday he was impressed with the way Gorton Tesco was managing the lockdown, managing a queue of people outside the store and keeping people two metres apart from each other when they got inside.
However, he said he went to another supermarket in Gorton, which he did not name, where the attitude seemed to be 'what coronavirus?'.
Some people appeared to treat the crisis as 'a holiday' and were walking out of the store with trolleys 'full of booze and charcoal', he said.
Social distancing inside the store was 'completely failing' and even staff members raised concern that their health was being out at risk, he said.
"People have got to take this seriously. This is not a holiday. This is about saving lives," said Mr Hopkins, speaking on Mike Sweeney's BBC Radio Manchester show.
Some rogue drivers, because the roads were largely empty, were driving at 'ludicrous' speeds, he said/
One motorist was clocked down 75mph in a 30mph zone, he said, adding that on his way into work he had seen people approaching 100mph on the motorway.
"Everybody thinks now that the roads around Greater Manchester are a race track," he said.
He added: "Please, treat the roads safely because if you are in an accident its tying up NHS resources and it's tying up our resource and it's putting everybody at risk of further infection."
