POLICE said today they had arrested four people over the murder of a 15-year-old boy shot dead in his bedroom at his home in south London.

Michael Dosunmu, who had just celebrated his 15th birthday, was gunned down on Tuesday at his house in Peckham, south London.

Detectives said they had arrested four suspects yesterday evening and they were now being questioned at police stations in south London.

Police said Dosunmu was a quiet, church-going schoolboy whose background gave no clues as to why he would be targeted and suggested he might have been a victim of mistaken identity.

"Michael was an innocent boy who has been killed in cruel and tragic circumstances," said Chief Superintendent Malcolm Tillyer said yesterday.

"My heart goes out to his family."

The gunmen are thought to have specifically targeted the house in Peckham but killed the wrong person, Scotland Yard said.

"We believe that they were targeting the premises, but it's possible that they weren't necessarily targeting him individually," a spokesman said.

"It is possible that it wasn't him that they were after."

The killing was the third in three days in south London.

On Saturday, a 21-year-old man was stabbed to death close to the boy's home while James Smartt-Ford, 16, was shot dead a few miles away at Streatham ice rink. Police have not linked the deaths.

Two gunmen burst into Dosunmu's house in the early hours of Tuesday and shot him in his bed, the family's vicar said.

"His father told me that his daughter heard a gunshot, then a bang as somebody kicked the door open and came in to the house," the Reverend Julius Shabiaba, of the Celestial Church of Christ, told the Daily Mail.

"They went to her bedroom, so she covered her head with the duvet. They came in and pulled the bedclothes off, but she pretended she was sleeping.

"Maybe they knew who they were looking for because they went out and did the same to her brother Michael – but then shot him in his bed."

He was a "perfect sweet and gentle boy", he added.

The shooting took place close to where schoolboy Damilola Taylor was stabbed to death in a stairwell in 2000.

The area was later portrayed in court as a crime-ridden neighborhood with poor housing estates terrorized by gangs of youths.

Since the 10-year-old's death, the area has seen huge investment with estates demolished and new facilities built for young people.

The changes have led to a fall in crime and better school attendance, police and council officials say.

Chief Superintendent Tillyer said the area had improved and crime was committed by a tiny minority.

"This tragedy also has a significant impact on the local community," he said. "I would hate to think that the media will paint a picture of Peckham as an unsafe area. The reality is that levels of crime have reduced year-on-year.

"The vast majority of the community, young and old, are hard working and law abiding. They abhor what is going on as much as anyone

MAY HIS SOUL REST IN PERFECT PEACE