Police officers fired shots in a major operation to disrupt a suspected tiger kidnapping near Magherafelt.
Police fired two shots during the operation close to Aughrim Road around 1am on Friday.
It is understood three men were arrested at the scene while a fourth man was later apprehended.
A house close to the scene of the shooting remained sealed off yesterday while police armed with machine guns guarded the entrance.
A nearby laneway also remained cordoned off while police forensics experts wearing white overalls worked in a field to the rear of the house.
Police last night confirmed the planned operation was led by the PSNI’s Organised Crime Branch.
Shocked locals say they were alerted to the incident when flares fired by police lit up the night sky. Seconds later dozens of police officers flooded into the area as a PSNI helicopter hovered overhead.
A spokeswoman for the PSNI was remaining tight-lipped about the incident last night.
She said: “Detectives from the PSNI Organised Crime Branch have arrested four men during a proactive operation. There are no further details.”
A spokesman for the Police Ombudsman’s Office confirmed investigators were at the scene of the incident yesterday.
He said: “The Police Ombudsman's Office is investigating the circumstances in which police discharged two shots near Toome, Co. Antrim, in the early hours of this morning.
“The shots were fired at around 1am close to the Aughrim Road.
“As with all discharges of police firearms in Northern Ireland, the incident was referred by the PSNI to the Police Ombudsman for independent investigation. Police Ombudsman investigators have been at the scene and their enquiries in the area are continuing.”