AT&T has partially shut down 16 cell phone towers across Oakland, CA, in response to an FCC investigation that blamed the structures for interfering with police radio systems. According to the San Francisco Chronicle, city officials and the FCC notified AT&T of the interference last week, informing the carrier that its 850 MHz (2G) frequency was causing radio failures among police and firefighters. In response, AT&T suspended its 2G frequency at the 16 cell towers on Saturday, while promising minimal consumer impact. The company's 3G and 4G services remain intact, as do other 2G frequencies.

Oakland police have been experiencing problems with their radio system for the better part of a year now, most notably in July, following a visit from President Barack Obama. But officials weren't able to identify the culprit until earlier this month, when investigators noticed that radio signals became significantly weaker around specific cell towers. According to David Cruise, the city's public safety systems adviser, police radio systems were especially hindered within a quarter to a half mile of a given tower.

In a statement to Ars Technica, AT&T spokesman Seth Bloom described the shutdown as a "cautionary measure," adding that the company is working closely with the city to determine whether "the issues they’ve raised are connected in any way to AT&T’s network." City officials are also looking into cell towers operated by T-Mobile, which runs a frequency that could pose similar issues for police radio systems. FCC regulations give priority to spectrum used for public safety communications.

"Our investigation is continuing," Cruise told the Chronicle. "This is not the end of it, for sure. There are plenty more issues we're looking at. We're working on plans to remove all of them."