An unarmed policeman has been shot in the arm while chasing three men in south London.
The constable, who has not been named, was hit when one of the men opened fire in Kingsdown Avenue, south Croydon, at about 2200 BST on Friday.
His injuries are not said to be life-threatening. Two men, aged 21 and 22, have been arrested on suspicion of attempted murder.
An 18-year-old was held on suspicion of causing grievous bodily harm.
The teenager, who was also arrested on suspicion of possession of drugs, was later bailed until early September.
A spokesman for the Metropolitan Police (Met) said officers were called when a group of men were seen acting suspiciously but the men ran off when a patrol arrived.
He said as the officers chased the suspects on foot, one suspect produced a handgun and shots were fired.
Commander Tony Eastaugh said: "I am outstandingly proud of our officers who put themselves in positions of danger on a daily basis to protect the communities of London.
"It is sad that an unarmed officer has been shot whilst performing his duty to the public. Our thoughts are with him and his family."
The incident is being investigated by Operation Trident, the Met's unit dealing with gun crime in London's black community.
The police officer is the second to be seriously injured in Croydon in the past two months.
A plain-clothes Pc serving with the Broad Green Safer Neighbourhood Team was stabbed on 19 May when he stopped a gang of youths in Bute Road, Broad Green.