He said this was paving the way for new groups to wage another campaign of anti-social behaviour and drug-related criminality in Mexborough.
Scott Fitzgerald, aged 22, was the 10th Pitsmoor Shotta Boy gang member to be jailed this year after he admitted attacking a woman with a metal bar.
Inspector Richard Collingwood said since the conviction officers have seen a spike in anti-social behaviour, with yobs throwing bricks and fireworks at police cars – and smashing the windscreen of a moving police car with a brick.
Officers are responding to the problems by putting in place high visibility patrols in Mexborough.
Insp Collingwood said: “We have had a lot of gang members locked up now, but this has created a sort of vacuum, making way for multiple gangs to come into Mexborough and start causing trouble again.
“This is all related to drugs.
“Over the last week we’ve had bricks thrown at police cars.
“During one incident last week we had a brick thrown through the window of a police car, shattering the windscreen.
“We’ve also had fireworks thrown at police cars over the last few weeks so there does seem to be a few problems in Mexborough again but we want to reassure members of the public that we are keeping a close watch on what’s going on.
“We’re also due to have more CCTV installed in the affected areas.”
Insp Collingwood has identified Oliver Street and Schofield Street in Mexborough as among the problem areas.
Fitzgerald, of Beaumont Mews, Manor, Sheffield, was jailed for eight-and-a-half years. The other nine members of the Pitsmoor Shotta Boys were jailed for a total of 33 years at Sheffield Crown Court last month after pleading guilty to a range of offences including violent disorder, drug possession, witness intimidation and robbery.
Mexborough First councillor Sean Gibbons encouraged members of the public to help officers in the crime clampdown by reporting every incident to police or crime-busting charity Crimestoppers.
He said: “We know things in Mexborough could be better and that people are concerned about some of the crimes that have been taking place.
“All three Mexborough councillors are working to make Mexborough a better place to live, work and visit.
“And with issues like this we fully support police and the action they are taking.
“We need people with any information to keep coming forward to police.”
Community leader and former police officer Frank Knapton MBE said new gang members coming into Mexborough was almost inevitable – but added he had ‘complete confidence’ the police would work to stamp out any problems.
The 79-year-old said: “We are all pleased with the swift and efficient way the police have dealt with some of the serious problems in Mexborough.
“We are also very grateful for the extra funding being put in to stop some of these problems and by the support of Police and Crime Commissioner Dr Alan Billings.
“Residents have felt relieved since the convictions, although I have heard a few things about trouble starting again.
“But I have complete confidence that Richard Collingwood and others will tackle the problem head on – like they have with the gang recently.
Mr Knapton, of Morton Road, Mexborough, encouraged anyone with concerns to attend the next Partners And Communities Together meeting at the rear room of Mexborough Library at 6.30pm on Thursday, April 14.
The meeting is due to be attended by representatives of Doncaster Council, South Yorkshire Police and St Leger Homes.