A woman is fighting for life in hospital after she was stabbed in a home in East Dulwich.
Nearby Barry Road was closed on Friday night due to the incident and local bus routes had to be diverted.
The victim was taken to hospital where is currently in a life-threatening condition, the Metropolitan Police said.
A man has been arrested on suspicion of attempted murder and has been taken into custody at a South London police station.
A spokesperson from the force said: “Officers attended along with London Ambulance Service.
“A 36-year-old woman was found with stab injuries and taken to hospital.
“She remains in a life-threatening condition.
“A man was subsequently arrested on suspicion of attempted murder.
“He has been taken into custody at a south London police station.
“A crime scene remains in place and enquiries are ongoing.”