A man and a teenage boy have been rushed to hospital after a double stabbing in south London on Good Friday.
Police and paramedics raced to the scene of the incident on a busy road in Tulse Hill shortly before 4.30pm.
Two men, aged 18 and 20, were taken to hospital. The 20-year-old had been stabbed in the chest while the teenager had suffered a cut to his hand, police said.
On Saturday police said the man whose chest had been punctured remains in hospital. His condition is not thought to be life-threatening.
The other man, aged 18, was discharged from hospital and then arrested on suspicion of grievous bodily harm.
Two other teenage boys, aged 18 and 16, were arrested at the scene and taken to a south London police station where they remain in custody.
Detectives from Lambeth CID are investigating after the stabbing, which happened at the junction between Tulse Hill Gyratory and Norwood Road.
Any witnesses, or anyone with information that may assist police, should call Lambeth CID via 101.
To give information anonymously contact Crimestoppers on 0800 555 111 or via the crimestoppers-uk.org web site.