Police officers sustained minor injuries while dispersing hundreds of people from illegal raves held across Greater Manchester last weekend.
Mayor Andy Burnham said the events continued to be a ‘real concern’ during lockdown and urged parents ‘not to turn a blind eye’ to the risks.
Greater Manchester Police’s intelligence gathering has also ‘much improved’ having encountered numerous illegal gatherings in recent weeks, he told a press conference on Wednesday.
The first gathering disrupted by force was in Smithills Country Park in Bolton on the evening of Friday July 10.
Mr Burnham said the event was broken up without incident and that a sound system was seized.
Then late on Sunday July 12 on an industrial site in Oldham, police used a dispersal order to disrupt an event attended by 250 people.
“There were three arrests and some minor injuries sustained by officers, which is completely unacceptable,” added Mr Burnham.
On the same night GMP dispersed a rave held in Manchester which was attended by 300 people.
Members of the public are still being encouraged to call 101 if they hear of any similar events taking place in the future.
Mr Burnham said: “There is no security, no proper organisation, and of course there’s the risk of spreading the virus.
“We ask you to bear all of those things in mind, and we say to parents please don’t turn a blind eye, or worse, drop your son or daughter off at one of these events.
“I’m grateful to GMP who have worked hard to really disrupt these events where they possibly can.
“We have very much improved our intelligence gathering and our response to these events which continue to be a real concern.”