One man has died and at least nine others have been injured in a spate of stabbings in south London.
Police were called to five reports of stabbings in Croydon on Friday evening.
There is no information at this stage to suggest the incidents are all linked, the Metropolitan Police said.
A Section 60 Order granting additional stop and search powers was in place across Croydon on Saturday morning, the force said in a statement.
Police were called to five incidents of serious violence between shortly before 19:00 GMT and just after 21:00 on Friday.
One man was pronounced dead at the scene at Wisbeach Road, Croydon, while another man was also taken to hospital.
Two other men suffered life-threatening injuries and two people were arrested in separate incidents.
Speaking on Friday night, Det Supt Nicky Arrowsmith said the city had seen “a number of needless and completely abhorrent violent altercations, including one that has tragically resulted in a loss of life”.
She said teams from the Violent Crime Taskforce and Territorial Support Group had been deployed to help “deter and prevent any further violence”.
The force has urged anyone with information to contact officers or anonymously through Crimestoppers.
Labour MP for Croydon North Steve Reed said in a tweet that the “absolutely horrific news” would “devastate our community”.
He added his thoughts were with those who had been injured and the police and medical staff dealing with the situation.