Two people have been stabbed to death in London in separate attacks within 40 minutes of one another.
An 18-year-old man is in a critical condition after a third separate stabbing three hours later, on Sunday.
More than 35 people have been stabbed to death in the capital so far in 2018.
A woman, 34, was arrested on suspicion of murder at the scene of the Colindale attack.
Police said they were called at 17:58 BST on Sunday to Zenith Close and found a man with stab wounds. He died in hospital later that evening.
Police said the victim and suspect were known to one another. A crime scene is in place and inquiries continue. A man in his 20s has been arrested on suspicion of murder over the Brixton death.
At 18:36 BST officers were called to a home in Sudbourne Road, where a woman in her 30s had been attacked. She was pronounced dead at the scene. Her next-of-kin have been informed, police said.
In the separate attack on Alexandra Palace Way, Haringey, a 19-year-old man was arrested near to the scene on suspicion of affray. He was taken into custody at a north London police station.