Iraq's authorities have said the state of emergency which gives them special powers to fight insurgents is being extended for another month.
Violence continued with the discovery of 18 bodies near Mosul
The extension was needed because "gangs of terrorists" continued to disrupt the political process, the interim PM said.
As violence mounts ahead of the 30 January poll, it has emerged that 18 Iraqi men recruited to work at a US base near Mosul have been murdered.
Their bodies were found in a field outside the northern city.
The labourers, all Shia Muslims from the Nasiriya area in the south of the country, had apparently been recruited by a contractor from a casual labour market in Baghdad.
They were sent up to the Mosul area in minibuses in early December, ostensibly to work at the US military base there.
Whether this was a deliberate trap is not known, but the buses were intercepted by gunmen and the workers disappeared, said the BBC's Jim Muir in Baghdad.
Their families became anxious about their fate, went to Mosul to investigate and eventually found the bodies of all 18 in an area to the west of the city known as a hotbed of the insurgency.
They had all been shot in the head and body.
The bodies, now in a state of decomposition, were brought back down to Baghdad where they were claimed by relatives and taken home to the south for burial.
The abduction and killing of ordinary people working with the American forces has become commonplace, especially in the Mosul area, but it is unusual for such large numbers to be killed in one single incident, our correspondent says.
Mosul, a predominantly Sunni city 360 km (225 miles) north of Baghdad, has recently been a centre of insurgent activity.
A suicide attack on 21 December in a mess tent at a US base near Mosul killed 22 people, including 14 American soldiers.
Dealing with violence
Violence in Iraq has been steadily mounting over recent weeks and has been claiming dozens of lives every day.
The extension of the state of emergency comes as no surprise in these circumstances, correspondents say.
The emergency rule was first imposed for two months in November last year ahead of a major assault on the rebel stronghold of Falluja.
The measures include powers to impose curfews and close borders and airports.
They also allow the government to detain people suspected of being part of the insurgency without following normal legal procedures.