A suicide bomber killed three people and wounded 165 in northern Iraq on Monday, while four people were killed in shootings elsewhere in the country, security and medical officials said.
The bomber struck at a police station in the town of Dibis, northwest of the ethnically mixed oil city of Kirkuk, district official Abdullah al-Salehi told AFP.
Many of the wounded were pupils at an adjacent Kurdish girls' secondary school, Salehi added.
Sadiq Omar Rasul, the head of the Kirkuk health department, said the bombing killed three people and wounded 165.
Dibis is part of a swathe of territory that the Kurds want to join to their autonomous region in northern Iraq, over the objections of the federal government in Baghdad.
Diplomats say the dispute poses the biggest threat to Iraq's long-term stability.
Elsewehere, gunmen killed one person in the Al-Amil district of Baghdad and another north of the capital, security and medical officials said.
Gunmen also killed a blacksmith near Baquba, north of Baghdad, and a soldier in the main northern city of Mosul.
The violence came a day after attacks killed 11 people, including an anti-government protest organiser and a city council member.
No group has claimed responsibility for the violence. Militants in Iraq carry out attacks against both security forces and civilians in a bid to erode confidence in the government.
Violence has decreased from its peak in 2006 and 2007 when sectarian bloodshed raged between Sunni and Shiite Arabs.
But 10 years after the US-led invasion, attacks remain common, killing 220 people last month, according to an AFP tally based on security and medical sources.