A man has been shot dead in London and three men have been injured in two separate shootings in Manchester.
Police cordon off one of the streets in Manchester
Craig Thoms, 28, of Leyton, east London, was found with fatal gunshot wounds in a car in Hackney, early on Saturday and died later in hospital.
His death comes in the wake of the gun killings of three teenagers in south London in less than two weeks.
In Manchester, three men are in hospital after being shot in the two attacks, in Moss Side and Longsight.
Armed police have been patrolling some of the affected areas.
Following the killing in Hackney, police are searching for two black men seen making off towards Digby Road.
Mr Thoms was shot as he went to get out of a grey Fiat Punto outside the Eko restaurant in Homerton High Street at about 0530 GMT.
He was taken by ambulance to Homerton Hospital, where he was pronounced dead 15 minutes later.
Det Supt Gary Richardson, of the Metropolitan Police's Operation Trident unit, said: "Almost immediately he was approached by two gunmen who opened fire.
"He immediately put the vehicle into reverse and drove some 80 metres up the road, being chased by the two gunmen. The vehicle crashed into a parked vehicle.
"He attempted to get out and was immediately attacked again by the two gunmen who shot him in the street."
Det Supt Richardson said they knew of no motive for the shooting but that it was "clearly a targeted incident where this individual was picked out".
Armed officers were deployed on south London streets overnight in Operation Neon following the shootings there and carried out searches of suspicious vehicles.
Billy Cox, 15, of Clapham, who was killed on Wednesday, died from a gunshot wound to the chest, a post mortem has said.
His shooting followed the deaths of James Andre Smartt-Ford, 16, and Michael Dosunmu, 15, who were gunned down in Streatham and Peckham respectively.
In Manchester an 18-year-old man was shot in the back while he was standing with friends outside Millennium Powerhouse Youth Club on Raby Street, Moss Side, at about 2100 GMT on Friday. The victim has a bullet lodged in his sternum.
Hours later, two men aged 19 and 27 were shot in a Nissan Primera car at the junction of Stockport Road and Dickenson Road in Longsight.
None of the injuries are thought to be life-threatening.
Ch Supt Dave Keller, of Greater Manchester Police, said: "This problem is only caused by a small number of individuals who are engaged in this, and we are actively targeting these individuals."
Meanwhile in Peckham community leaders gathered on Saturday to protest the sale of replica guns on the streets.
DJ Prophetess told BBC News: "I feel that gun crime is like a disease that has not been treated and so it has spread and got out of hand."
In response to the killings, Home Secretary John Reid announced he was investigating handing out tougher sentences to tackle gun crime and gang culture.
"We also need to make people face up to their responsibilities as parents and families and last but not least we need to empower local communities," he said.
But Professor Rod Morgan, who last month resigned as head of the Youth Justice Board, told BBC Radio 4's Today programme tougher sentences would be of "very little relevance".