The Philadelphia Police Department said Thursday its emergency 911 call center has had sporadic difficulties with incoming cell phone calls. In some cases, the dispatcher cannot hear the caller's voice. However, the caller's phone number is displayed on the dispatcher's computer screen and a police radio unit immediately contacts the caller's cell phone, according to police.

Verizon, the Police Department's service provider, has been working with cell phone carriers to resolve the problem. Police say the problem is not caused by the department's hardware or software components. - Inquirer staff