A boy who knocked on a neighbour's door for help after being stabbed has died in hospital, police have said.
The 15-year-old, named locally as Reece Tansey, suffered "several stab wounds" in Walker Avenue, Bolton at about 04:45 BST, Greater Manchester Police said.
The force said formal identification had not taken place, but a murder investigation had begun.
In a statement, Harper Green School in Farnworth, which he attended, said his death was "a total tragedy".
"The school community is shocked and saddened by this terrible news and our thoughts are with the student's family and friends at this difficult time," a spokesman added.
"For a life to be ended at such a young age is a total tragedy."
Friends of the teenager have released balloons in his memory on Harper Green playing fields.
Speaking to BBC North West Tonight, they said he was "a good kid" who "made everyone laugh".
One boy said it was "tragic when we heard the news".
"Everyone was just quiet. He was a funny guy and he was well-known in the school," he said.
No arrests have been made.
Det Supt Chris Bridge said Reece's death was a "huge shock to the community".
Appealing for information, he said his officers were "doing all we can to piece together what happened and find those responsible".
"There will be an increased police presence in the area whilst we carry out a number of lines of inquiry and anyone concerned... can speak to our officers," he added.