A suicide bomber wearing an explosives belt killed at least 21 people, mostly Shiites, on Friday in a town north of Baghdad, shattering what had been weeks of relative calm, the town's mayor said.
The blast in the town of Balad Ruz emphasizes the delicate nature of Iraq's security gains and comes as the country is approaching its eighth month without a new government since the March elections.
The suicide bomber blew himself up inside a popular cafe in the town of Balad Ruz, 45 miles (70 kilometers) northeast of Baghdad as people were gathered to play dominoes and drink tea, said the town's mayor, Mohammed Maaruf. An additional 65 people were injured, he said.
The neighborhood where the explosion occurred is home to many Faili Kurds, a small sect of ethnic Kurds following the Shiite branch of Islam, and many of the dead were Shiites.
Although there was no immediate claim of responsibility, blasts targeting Shiites are often the work of Sunni insurgents trying to stir up sectarian problems.
While scattered violence occurs almost daily in Iraq, Friday night's blast broke what has been a time of comparative quiet across Iraq. The last such major attack came Sept. 19 when twin bombings in Baghdad killed at least 31 people.
Diyala province, with its mixed population of Sunnis, Shiites and Kurds, was once one of the most volatile in Iraq but recent years has seen a drop in violence.
Also on Friday, the New York-based Human Rights Watch denounced the Kurdish regional government's investigation into the slaying of a Kurdish journalist critical of authorities in Iraq.
Freelance journalist Sardasht Othman's handcuffed and bullet-ridden body was found near the restive northern Iraqi city of Mosul and authorities concluded he had been killed by insurgents.
Many Kurds in the autonomous region where he lived, however, blamed the government for his killing and staged dozens of huge protests demanding the perpetrators be brought to justice.
"The Kurdistan government needs to get to the bottom of this killing with an open and independent inquiry that will include looking into allegations of government involvement," said Joe Stork, deputy Mideast director of the New York-based Human Rights Watch.
Kurdish government officials have denied any involvement in Othman's death and in a report in September concluded that he had ties to Sunni militants in nearby Mosul who ultimately killed him.
In Baghdad, Justice Ministry officials said that a former member of Saddam Hussein's regime who used to head the feared Republican Guard has died in prison.
Ibrahim Abdul Sattar died Friday morning from liver cancer, said Deputy Minister Busho Ibrahim, adding that the cause of death was documented by both the U.S. military and the Red Cross.
A relative of Sattar's in the northern city of Tikrit, Saddam Hussein's hometown and a former stronghold his regime, confirmed that Abdul Sattar died due to illness, but did not want to be identified out of fear for his security.
His body will be handed over to family members on Saturday, said a police official from Tikrit who did not want to be identified because he was not authorized to speak to the media.
Sattar, who was born in 1948, was chief of staff for the Iraqi Army when Saddam's regime was toppled. His death comes days after another high-ranking member of Saddam's regime, Tariq Aziz, was sentenced to death on Tuesday.
Aziz was the international face of Saddam's government and a rare Christian in the dictator's inner circle. He was convicted and sentenced to death for charges related to a Saddam-led campaign that hunted and executed members of the Shiite Dawa Party, of which current Prime Minister Nouri al-Maliki is a member.