A teenager has been killed and another is critically injured following a knife attack in north-east London.
An area around the scene of the killing has been cordoned off
Paul Erhahon, 14, was stabbed to death in Leytonstone, and a 15-year-old boy injured in what is thought be an attack involving a large gang of youths.
Paul's mother cradled him in her arms shouting "help me, help me" as he lay dying, a neighbour has said.
A 13-year-old boy and a man, aged 19, were later arrested over the attack and are to be questioned by police.
Officers found the boys after being called to Crownfield Road, Leytonstone, shortly before 2000 BST.
They have not named the other teenager who was injured but said the victims, who were black, were friends and Paul Erhahon lived in Buttermere Close in Leytonstone, close to where the stabbing took place.
Det Ch Insp Matthew Horne said: "We understand a large group of youths were involved in an incident in the foyer of Gean Court, a block of flats in Langthorne Road E11, during which we believe the two victims were stabbed.
"It is believed they then managed to stagger the short distance to nearby Crownfield Road.
"A number of youths were seen running from the scene."
Police said the incident may be gang-related.
Elizabeth Chapkins, a neighbour who lives opposite the spot were Paul was found, said she rushed to help after she heard Paul's mother's frantic shout for help.
"She was saying 'we came to this country for a better life, we didn't come here for this'," said Ms Chapkins.
The neighbour saw Paul and his 15-year-old friend stumbling along the road but at first thought they were drunk.
Then she heard the screams when Paul's mother found her son slumped on the floor yards from his home.
"She (Paul's mother) lifted his shirt to show me and there was blood all over him. He must have been trying to get home to his mum," she said.
"He was barely moving, but he was going into unconsciousness and he could not speak. She was screaming blue murder.
"I don't want to hear or see anything like that again. There was nothing we could do."
A friend of Paul's, who did not want to be named, said Paul was also known as MC Hellrazor and was keen on jungle and garage music.
The 17-year-old also said Paul was part of a group of youngsters who lived in the area, called "the youngers", but stressed that it was not a gang.
LONDON'S TEENAGE VICTIMS
James Andre Smartt-Ford, 16, shot in Streatham, 3 February
Michael Dosunmu, 15, shot in Peckham, 6 February
Billy Cox, 15, shot in Clapham, 14 February
Kodjo Yenga, 16, stabbed in Hammersmith, 14 March
Adam Regis, 15, stabbed in Plaistow, 17 March
"I can't explain how I feel," he said. "He was a good lad. He was healthy, he did not smoke, didn't drink."
He said the boy attended Kingsford Community School, the same school as 17-year-old Adam Regis, who was stabbed in Plaistow, east London, last month.
Another friend, who gave his name only as Mich, has written about his grief on the website gonetoosoon.co.uk.
He wrote: "Just thought I'd write you a message to let you know how much you are missed.
"I know nobody's life will be the same without you."
A large area surrounding the estate has been cordoned off by police and several officers are guarding the scene.
More than half a dozen bunches of flowers have been laid near his home.
The latest attack follows the killing of five other young males in London in the past two months.