Iraqi authorities claim to have captured two leaders of al-Qaeda's network in Iraq.
Mr Kassim Daoud, minister of state for national security, gave few details of the arrests, but said capturing the members of Jordanian militant Abu Musab al-Zarqawi's group had made Iraq safer.
Zarqawi's group has claimed many of the deadliest suicide attacks in Iraq since the fall of Saddam Hussein, and has beheaded several foreign hostages.
He is regarded as the most dangerous militant in Iraq and has a $25 million bounty on his head.
In the run-up to the poll on Sunday, Iraqi officials have announced the capture of several suspected insurgent leaders.
But some senior officials have privately cast doubt on the announcements, saying they are aimed at creating a positive impression ahead of the elections.