Niagara Falls police are now searching for a city man following a standoff spurred by the rescue of a woman found chained in the basement of a city home on Sunday.

Falls police had surrounded the home of Michael Ciskiewic, 25, on the 3000 block of Monroe Avenue on Sunday afternoon but after a standoff that lasted about 12 hours, it was determined that he was not in the home after officers broke the home’s windows and used CO2 gas in an effort to end the standoff. Niagara Falls Detective Captain Kelly Rizzo said because of the use of gas, police will need a day or so before they can enter the house to collect any evidence.

The incident began about 1 a.m. Sunday when officers were called to 3070 Monroe Ave. for a report of an assault involving a woman. Responding officers could not locate a victim at the time.

Later Sunday, Rizzo said Falls police began receiving calls from family members of the woman who they said was missing. Police responded to investigate and eventually used a blood hound to track the woman. She was located a few houses away. Officers found blood leading up to the back door, Rizzo said, breached the door and found the victim chained up in the basement.

She was taken to Erie County Medical Center for treatment.

Early Monday morning, Rizzo said the woman was recovering and doing well considering the circumstances that she had endured.