Ban "underscores the pressing need for dialogue between political blocs in order to overcome the current crisis," his spokesman Martin Nesirky said.
He said the UN chief was concerned about "the escalating political tensions and the appalling upsurge of violence that has killed a high number of civilians over the last two months."
"He urges all parties to redouble their efforts to ensure that the momentum of national reconciliation is not lost to those groups that strive to reignite sectarian violence in Iraq," Nesirky added.
No group has claimed responsibility for the latest violence, but Sunni militants linked to Al-Qaeda have in the past launched coordinated nationwide bombings in a bid to undermine confidence in the security forces and the Shiite-led authorities.