A teenage boy was ambushed and fatally stabbed with a machete by two balaclava-clad attackers as he walked through a west London churchyard, witnesses said.
The 17-year-old was attacked as he walked past the Church of St Mary on Paddington Green in front of horrified bystanders including students at City of Westminster College which is next to the crime scene.
The killers struck just after 1.40pm on Monday.
Staff from the college raced to help the fatally injured boy as police and paramedics rushed to the scene.
The victim was not a student at the college.
A witness said: “There were two attackers with their faces covered. The boy was walking through the churchyard and they jumped on him. They had a machete and stabbed him it looked like under the armpit.
“He lay there and staff and security at the college came out to try to help him. Then the paramedics came and everyone worked so hard to save him. Everyone is devastated.”
The air ambulance was dispatched to the scene along with dozens of police officers. Forensics officers have been trawling the scenes for clues.
Another witness said: “After the stabbing the boy’s family came. The mother was in a terrible state, they were all crying. There were dozens of families and friends. They said the boy was wonderful. A joker loved by everybody.”
The boy is said to be an avid boxer from the Kurdish-Iraqi community.
A tribute left with roses at the scene said: “Rest in peace. 17 is no age to go, you will not be forgotten. From A Level politics and sociology.”
Another witness claimed on Facebook: “I tried to save him, I saw the whole incident. When you hear the mum scream, then you know -devastating!”
She added: “I’m no hero, these kids pushed me aside, shouting at him, I tried to keep his wound compressed but they were moving him around too much.
“The teachers and first aiders helped but he went into cardiac arrest soon after, I knew he was deteriorating... I managed to get his name.”
A Scotland Yard spokesman said: “Officers found a boy, believed to be 17, with a stab wound.
“Despite the best efforts of the emergency services, he was pronounced dead at the scene just over 30 minutes after the 999 call was received.
“Next of kin have been informed.”
Police cordoned off the area around the body and several officers stood at entrances to the green. No arrests have been made as police trawl through CCTV footage from around the area.
Local MP Nickie Aiken tweeted: “Very sorry to learn the police are investigating a murder in Paddington. My thoughts are with the family and friends of the victim.”
In a separate stabbing, in Leytonstone a man was found with serious knife wounds after a collision between two cars. The incident happened on High Road Leytonstone at around 1am today (Tuesday). The victim’s injuries are not thought to be life-threatening
Any witnesses or anyone with information on either crime is asked to tweet @MetCC or call 101. To remain anonymous contact the independent charity Crimestoppers on 0800 555 111.