More than two dozen law enforcement officers, including two SWAT teams, served search warrants on four homes in the normally quiet Napa County city of Calistoga on Thursday, a case connected to a series of burglaries in the area.

"Because of the nature of their crimes and the fact they were armed, the SWAT teams secured the area" before detectives moved in to search the houses, Napa County Sheriff's Capt. Tracey Stuart said.

Officers from the Sheriff's Office, Calistoga police and Napa police participated in the raid. No arrests were made, she said, but the investigation is continuing.

Stuart declined to say exactly what detectives were looking for but confirmed that the operation was connected to two January burglaries on a rural road south of Calistoga. In those cases, a handgun and a vintage shotgun were taken from one house, and owner's manuals and keys were stolen from vehicles at another.

Stuart said there are at least four suspects and there may be additional cases tied to the investigation, although she declined to elaborate or identify the people involved.