A one-year-old girl and a three-year-old boy have been stabbed to death in east London.
Police were called to reports of a man and two children injured in Aldborough Road North in Ilford at about 17:30 BST on Sunday.
The girl died at the scene while the boy died in hospital, the Metropolitan Police said.
A 40-year-old man was taken to hospital in a critical condition, where he remains.
Police said all three were known to each other.
Detectives have launched a murder investigation, although the Met said it was not looking for anyone else in connection with the deaths.
Thomas Dodds, 78, who lives about 20 yards from the scene, described hearing a woman scream before police cars and ambulances arrived.
He said: “It sickens me, a young baby and a three-year-old. Someone who did that doesn’t have a heart, to put a knife into a baby.”
A nurse who lives on the road, who asked not to be named, said she “knew something nasty and serious” had happened when an air ambulance arrived.
She added: “I couldn’t sleep last night.
“I knew something terrible had happened but when it came out that two children had died, I was shaken.”
Jas Athwal, leader of Redbridge Council, tweeted: to say his thoughts were with the family and wider community “who are grieving this unspeakable tragedy”.
There have been 21 fatal stabbings in London so far this year – six of them in the borough of Redbridge.
On 20 January three men – aged 29, 30 and 37 – were stabbed to death on Elmstead Road in Seven Kings and 24-year-old Ricardo Fuller was also fatally stabbed outside a nightclub near Ilford High Road on 7 March.