Thieves looking for copper have forced their way into 11 Oakwood homes that are vacant or for sale during the past two weeks.

“We think they’re operating under cover of darkness. We have some leads, but have made no arrests,” said Maj. Randy Baldridge, assistant director of Oakwood’s Police, Fire and EMS services.

Police estimated total losses at more than $10,000 in copper pipe and tubing, plus about $2,500 in other items.

Many of the addresses are east of Far Hills Avenue. Two have been hit in the 400 block of Monteray Avenue, along with others on Wiltshire Boulevard, Corona Avenue, Orchard Drive and Shroyer Road.

Another house on Kramer Road, adjoining the Dayton Country Club, also is on the list of break-ins police have responded to between Jan. 26 and Feb. 3.

Although thieves took only $350 worth of copper at the Kramer Road address, they did additional damage to the furnace and air conditioning units to reach the metal.

The Kramer Road home, which won an architectural award in 1926, “has never been broken into before,” said owner George Stanley, who is renovating it for sale. “I’m very surprised.”

“It’s disheartening,” said realtor Gay Spiegel, the listing agent for the property. “The thieves were very professional. They knew exactly what they were doing. They even turned off the water first,” she said.

Baldridge added, “There have been a lot of these kinds of crimes in the area, but we weren’t part of this until about two weeks ago.”

“While they may only be taking $200 to $300 worth of copper, another of my clients in Oakwood was left with $11,000 in damage when a ceiling was torn out to get to the pipes. The sad thing is that standard insurance policies often don’t cover vacant properties,” she said.

Spiegel said motion detectors will be installed around the Kramer Road home to deter a repeat visit. “That’s probably what everyone should do if they don’t have a security system.”

Baldridge said residents in neighborhoods where homes are vacant or are for sale should keep an eye out for anything suspicious “and contact us if they have any concerns.”

Copper pipes estimated at being worth $150 were taken during a break-in on Shroyer Road, but so were a washer and dryer valued at $1,000.

Pipes and an air conditioner coil worth $2,500 were removed from a residence on Deep Hollow Road sometime between 5 p.m. on Jan. 31 and 11:30 a.m. on Feb. 2, when the owner discovered it. Forced entry was through a side door.

Entry was forced through the front door of a house in the first block of Wiltshire Boulevard, where police estimated $2,500 worth of piping was removed. Two iPods and 200 music CDs valued at $1,000 also were reported stolen.