Three men were stabbed in Croydon on Monday.
An altercation that started inside McDonalds, North End is believed to have escalated outside the restaurant. Two teenagers were injured.
A third male, aged 20 presented himself at a south London Hospital suffering stab wounds to his face. Metropolitan Police believe these incidents are linked.
Officers found two 18-year-old injured males outside the restaurant; one suffered a stab wound to the arm, the other to the neck. They were taken to different London hospitals.
All three males have been arrested under suspicion of Grievous Bodily Harm (GBH), and remain in hospital with non life threatening injuries..
The Metropolitan Police confirmed that officers were called to the scene, and were not present during the incident. They also refuted an earlier report in the Daily Star that officers had been stationed on guard outside McDonalds the previous week.
Detectives are appealing to anyone who witnessed the incident, either outside or inside McDonalds, or further down George Street toward the station.
Anyone with information should call Croydon CID on 101 or call Crimestoppers anonymously on 0800 555 111 quoting reference 3813632/15.