A suicide bomber walked into a coffee shop, asked for a glass of water and then blew himself up on Sunday, killing 23 people in a northern town, as at least 25 people died elsewhere in Iraq.
Colonel Abbas Mohammed Amin, police chief of Tuz Khurmatu, 75 kilometres (50 miles) from the oil city of Kirkuk, said that 22 others were wounded in the bombing.
"The bomber wearing an explosive belt walked into the coffeeshop and blew himself up," Amin told AFP.
He said the bomber reportedly asked for a glass of water before detonating himself, bringing down the old building with the force of the explosion.
Elsewhere in Iraq at least 25 Iraqis were killed, as well as a British soldier.
The soldier was killed as British troops raided the tribal area of Garmat Ali, near the southern port city of Basra, to arrest suspects for "terrorist activities in Basra", British military spokesman Major Charlie Burbridge said.
He said another soldier was wounded in an exchange of fire during the raid which resulted in the detention of two "suspected terrorists", one of whom appears to be a local commander of a Shia militia, the Mehdi Army.
The soldier's death brought to 114 the British military's losses in Iraq since the March 2003 invasion.
In another incident two more British soldiers were wounded when a roadside bomb on the road to Al-Zubair, south-west of Basra, exploded next to their vehicle.
The incidents are part of a pattern of increased instability in the south which had once been considered relatively calm compared with restive Sunni central and western Iraq.
In Baghdad, the head of Iraq's Northern Oil Company (NOC) was kidnapped by gunmen on eastern Baghdad's Canal Street. His bodyguards were beaten and he was taken away.
Adel Kazazz is the Kirkuk-based NOC's general director and was in Baghdad to attend a meeting at the oil ministry.
Three people were killed and 32 wounded in a bomb attack at a market in the city's Karrada district, police said.
The province of Diyala, was the scene of a dramatic assault when a large group of insurgents stormed the main hospital of the provincial capital Baquba and freed several wounded comrades.
Four hospital guards were killed in the operation that targeted the third floor, which is reserved for detainees.
As police arrived at the hospital the insurgents set off a bomb in the front of the building and in the ensuing confusion made their escape.
Elsewhere in Diyala, a former official of ousted president Saddam Hussein's Baath party was killed in a drive-by shooting along with his son and a woman bystander. Two other civilians were killed in separate shootings in the province.
Also in Kirkuk, gunmen killed two brothers who ran a barber shop for giving Western-style haircuts, police said.
Three women were killed and six others were wounded in the northern city of Mosul when a suicide bomber blew up a car against a joint Iraqi-US patrol, police said. Three construction workers were also shot dead.
Five others were killed in different incidents, while five corpses were also found across the country.
Gunmen who seized 29 people, including top sports officials, in a daylight raid on a Baghdad club Saturday released six of their hostages Sunday.
Those freed included Nashat Maher, former head of military sports and now an advisor to the Iraqi Olympic Committee, the committee's office manager Mohammed al-Habash told AFP.
The coach of Talaba football club was also released, along with a driver and three other guards, he added.
Among those still held are the Olympic Committee's chairman Ahmed al-Hejea, its secretary general Amr Abdel Jabbar, the head of the Iraqi Tae Kwon Do federation, Jamal Abdel Karim, and the head of water sports, Saeb al-Hakim.
The Iraqi Football Federation has announced it was suspending all football games in protest at the kidnappings.