The victims, aged between 16 and 42, were driven by poverty in their village of Bayda in the relatively peaceful southern province of Zi Qar to seek work in Baghdad from where a mysterious contractor lured them north.
"The contractor did not accompany the workers but gave them an address in northern Iraq and told them to go there," said Naim Hussein Farhan Khafaji, who lost a brother in the massacre.
Distraught relatives of the men, who were almost all related, were gathering at a Baghdad hospital on Thursday to collect the bodies, which had all been found with a bullet to the head.
Mosul, a predominantly Sunni Arab city, has seen intensified violence and clashes between Iraqi and US forces and insurgents since mid-November when insurgents overran police stations there, prompting the force to quit en masse.
EMERGENCY LAW: Meanwhile, Allawi extended the country's emergency law - first put in place on the eve of the Fallujah assault in November - for 30 days to guard against attacks in the run-up to the elections.
The law gives the prime minister the authority to impose curfews, restrict movement between cities and set up round-the-clock courts where the government can go to obtain arrest warrants.
Iraq's neighbours met in Jordan for a conference expected to reiterate their commitment to elections on January 30, despite a dispute over whether to include an explicit reference to a principle of non-interference.
A US soldier was killed during an operation in restive Al-Anbar province, while the head of police in the Shia district of Sadr City, Abdel Karim, was gunned down in a morning ambush as he drove in the west of the capital.
Four Iraqi soldiers and three civilians were also killed in separate attacks in the north of the country.
But a chorus of influential voices, including Iraqi Prime Minister Iyad Allawi and US President George W. Bush, have rushed to reject growing calls to delay elections because of surging violence and a boycott by Sunni parties.
And the US ground commander in Iraq, Lieutenant General Thomas Metz, said insurgents in Iraq are 'thugs' who will not be allowed to stop the elections.
Metz warned that any delay would only increase violence in Iraq.