Bombings and shootings kill 31 across Iraq
A bomb near a cafe in Madain south of Baghdad killed at least two.
One report said the blast happened in a crowded cafe where people had been gathering after dark to break the daily Ramadan fast.
Correspondents say night cafes have become frequent targets of militants recently.
And the bodies of 14 Shia Muslims with gunshot wounds to the head were found at a fake checkpoint set up by Sunni militants 200km north of Baghdad.
Local officials said the checkpoint was maintained for half an hour, during which militants checked documents and summarily killed those drivers who they found to be Shia.
The attack followed a major assault on the nearby town of Suleiman Bek which drew security forces away from the road.
Thousands of people have died this year in a wave of unrest.
The attack comes three days after a mass prison escape.
A local al-Qaeda affiliate said it had organised the breakout, in which hundreds of inmates left two jails after an attack by gunmen.
On Thursday parliament speaker Osama al-Nujaifi warned that the escape could worsen the country's already deteriorating security situation.
Sunni militants summarily executed at least 14 Shiites on Thursday after setting up a roadblock north of Baghdad, stopping trucks and checking the IDs of drivers, Iraqi officials said.
The nighttime attack was reminiscent of the darkest days of the Sunni-Shiite sectarian bloodshed in Iraq in 2006-2007, when thousands of people were killed because of their religious affiliation or forced to abandon their homes under threat of death.
Lingering tensions between Sunnis and Shiites have been inflamed by persistent violence in Iraq and the civil war in neighbouring Syria, and there are growing fears that the country is slipping back towards all-out sectarian conflict.
Two local officials said some 150 militants carried out a coordinated operation during the night that included the highway killings, in the area of Sulaiman Bek, a town north of Baghdad.
The militants began by attacking the town itself with mortar rounds, rocket-propelled grenades and automatic weapons late on Wednesday.
Voice of Russia, Reuters, BBC, AFP