Police opened fire during a planned offensive on serious crime in Co Derry last night, it has emerged.
Four men were held after officers swooped last night on suspects they believed to be armed.
Two of them were spotted acting suspiciously in the Glenshane Road area, a Police Service of Northern Ireland spokeswoman said.
When they were approached one of the men had what appeared to be a handgun.
"As the men ran off police discharged three shots into the air," the spokeswoman confirmed.
Both suspects were arrested and an imitation gun seized. During follow up searches at an undisclosed location in Derry another two men were taken for questioning.
Northern Ireland Police Ombudsman Nuala O'Loan has launched an investigation after being informed that police fired shots.