Staff members said on Thursday their resignation followed threats they received in the past few days. The withdrawal of the Iraqi Islamic Party from the election also figured in their decision, Aljazeera has learned.
In its response, however, the electoral commission has vigorously denied the report. "That's not true. We have our staff in Mosul and al-Anbar," Abd al-Hussain al-Hindawi, the head of Iraq's Independent Electoral Commission, told AFP.
Al-Hindawi was also referring to the explosive province of al-Anbar, home to the strife-torn towns of Ramadi and Falluja. He declined to give staff numbers for Mosul, but said: "We have a larger staff than we did before across Iraq."
In a related move that could affect the 30 January elections, Shia leader Muqtada al-Sadr's political office announced it was taking legal action against the interim Iraqi government for alleged torture and murder of its members.
Fadhil al-Shara, an al-Sadr official, said the legal action focused on the Iraqi police in Hilla, who are alleged to have arrested 15 al-Sadr supporters in the town and tortured another four to death.
On Thursday, violence raged unabated throughout Iraq. In the southern town of Amara, an explosive device hit a British convoy and damaged one of its vehicles.
Anti-US fighters are in control
of large parts of Mosul city
The blast occurred in front of the headquarters of the British forces, which earlier came under a mortar attack from unidentified fighters.
In Mosul, a car bomb detonated as a US military convoy passed the western al-Yarmuk neighbourhood.
Mosul has witnessed intense fighting in recent days, with the US military announcing that a daylight assault on one of its compounds had resulted in the deaths of 25 Iraqi fighters and one US soldier.
Fifteen US soldiers were also wounded in the attack.
Also on Thursday, in Baiji, four Iraqis thought to have been working with US forces, were found killed inside their car while another Iraqi was killed by US fire in the Siniya neighbourhood, north of the town.
In al-Muatasim neighbourhood, south of the town of Samarra, US forces killed two Iraqis and wounded a third.
A US Humvee vehicle was destroyed when an explosive device detonated in the same town.
In Baghdad, two trucks transporting supplies to the US army were destroyed on the highway leading to Baghdad's international airport.
In yet another incident, this one in Hiyt, US forces raided the tomb of Abd Allah Mubarak and arrested four of the guards.
Oil refinery attacked
Late on Thursday, a mortar strike set fire to Baghdad's Dura oil refinery, an interior ministry official said.
Oil facilities are attacked on a
near-daily basis in Iraq
Baghdad firemen were struggling to put out the blaze and called for help at the refinery in the southwestern Baghdad suburb, the official said.
"We cannot stop the fire so we called other fire departments from outside Baghdad," the official said.
The attack occurred at 10pm (1900 GMT), the official said.
The Dura refinery is also home to Baghdad's main power plant.
The refinery provides fuel for the plant, which provides electricity for most of Baghdad and outlying areas.
It was not immediately clear if the fire had affected the power plant.
In Baghdad and much of Iraq, electricity is erratic, with households enjoying power sometimes for as little as three hours a day.