The schoolboy, who has not been named, was leaning on his bicycle next to other youths when a man jumped out of a car and opened fire.

The boy was hit in the chest, back, groin, buttock and thigh, police said. His 13- year-old friend was hit in the lower leg.

Detectives are still trying to find a motive for the attack, which happened at about 11.50pm on Saturday in Ardwick, Manchester.

Residents speculated that it may have been drug-related, after “turf wars” between rival gangs. One claimed that the gangs used teenagers to deliver drugs by bicycle.

There is no indication that either of the injured boys was involved in criminal activity.

Superintendent Gerry McGowan, of Greater Manchester Police, said that the children had been playing in the street when a silver car drove up and the masked gunman got out.

He said: “One male received five bullet wounds to his upper body and leg. Another male received a bullet wound to his lower leg.

“We cannot say what was the motive for the attack and early indications are that this is not a random attack, although we cannot say whether the youths who were hit were the intended targets.”

The group of about five youths had been playing on their bicycles on a grassy strip of land that links Billing Avenue with another residential street in South Manchester when the car pulled up.

Police said that up to five men may have been in the car. Witnesses said that the gunman stepped out of the car before opening fire, forcing the teenagers to scatter. Two were left lying on the ground, one of whom was bleeding heavily.

They said that the gunman was about 6ft (2m), had a muscular build and was wearing dark clothing and a balaclava.

An ambulance was called to the scene shortly before midnight, and the crew called the police.

The 15-year-old, who is thought to live within half a mile of where the attack took place, remained in hospital in a serious but stable condition, police said. The 13-year-old, from the Longsight district, was also receiving treatment.

Armed police stood guard outside the hospital. Officers were concerned that the attack may have been an attempted murder, and that the boys’ lives were still in danger.

There were about a dozen bicycles abandoned at the scene, which had been cordoned off with police tape.

Police were unable to confirm the type of weapon used and said that no firearms had been recovered.

The district of Ardwick lies about a mile south of Manchester city centre and has been plagued by drug and gang violence over recent years.

It is just east of the notorious Moss Side district of Manchester, which was riven by gang warfare of the 1980s and 1990s, earning the city the nickname “Gunchester”.

Further to the east lies Longsight, which is also a battleground for gang turf wars.

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