Thirty-four handguns were stolen from the Gun and Military Museum in Kuhmoinen, Pirkanmaa on Tuesday night, according to local police.
All of the stolen weapons are able to fire, according to Detective Chief Inspector and lead investigator Kari Aaltio.
He said that while none of the guns were loaded with ammunition when they were taken, they could still be loaded and fired.
"They are all handguns, so they're easy to carry, for example on the street. The fear is that they will fall into the hands of criminals," Aaltio said.
The stolen firearms included Nagant revolvers, Lahti pistols and Colt handguns.
Police are investigating the case as aggravated theft. During the investigation, the charges will be clarified.
Authorities have asked the public for tips in connection with the case. The police are particularly interested in a Toyota Avensis seen on the road in Kuhmoinen on Tuesday night.