Bloomberg reports that militants have bombed an Asiacell equipment building near Mosul, damaging the mobile phone operator's network and knocking out service in some northern areas.
The four attackers, some of whom wore military uniforms, held guns to the heads of security guards late on Thursday and planted four large explosives in a building housing routing and switching equipment, Asiacell chief executive Diar Ahmed said.
"One of [the devices] exploded and caused severe damage to the network. The other three were dismantled," Ahmed said. "It's a partial outage in (Nineveh) province but it's the majority to be honest."
The centre, located in a normally safe area in a Mosul free trade zone, just 60-70 metres from a police station, serves Nineveh province and parts of neighbouring Dahuk. Work crews hoped to restore service later on Friday.
Ahmed said he suspected the al Qaeda-affiliated insurgent group Islamic State of Iraq (ISI) was behind the attack. Mosul is considered an al Qaeda stronghold.
"The ISI has threatened our offices and our employees in Mosul many, many times because we work with the government," he said.
There were no reported injuries.