According to the police, shots were fired during a robbery on a delicatessen store in Cologne's wholesale market.
One of the three masked men is said to have shot an assault rifle in the air early Thursday evening, the police said.
Then the three alleged perpetrators are said to have fled in a car.
The wholesale market is located in the Raderberg district in the south of Cologne.
The police also used a helicopter during the search.
The officials initially did not want to comment on details of the attack.