A suicide bomber has killed four people and wounded dozens of others in the northern Iraqi city of Kirkuk.
The blast was heard across Kirkuk
The attack happened near the office of the Patriotic Union of Kurdistan Party, whose leader Jalal Talabani heads the US-appointed Iraqi Governing Council.
It came hours after a car bomb killed two people near the home of a pro-US council leader in the city of Ramadi.
In Baghdad, meanwhile, an Iraqi security guard was killed by gunmen outside the Jordanian embassy.
The powerful explosion rocked Kirkuk, throwing up a cloud of black smoke and shaking buildings across the city.
"I was walking in the street when a car exploded," said Hussein Ali, 52.
"I didn't know if it was night or day."
The Patriotic Union of Kurdistan Party's (PUK) office was damaged by the blast.
A school mistress and two pupils were among the dead, French news agency AFP reported.
In other violence on Thursday, two gunmen opened fire at the Jordanian embassy before dawn, killing the guard.
The Jordanians moved to the premises after their former embassy was struck by a car bomb in August, which killed at least 19 people.
In an earlier attack apparently aimed at a pro-US target, a car bomb exploded occurred outside the Ramadi home of Sheikh Amer Ali Suleiman - a leader of the Duleim tribe, one of the main Sunni tribes in Iraq.
The sheikh was not hurt, but hospital sources said two people were killed and at least 11 people were injured.
Sheikh Suleiman has been advocating co-operation with the US-led coalition in Iraq.
Ramadi - about 100 kilometres (60 miles) west of Baghdad - is located in the Sunni Triangle, where anti-US attacks are concentrated.
There have been dozens of car bomb attacks since Iraq came under US control in April.
For the past week, the US military has stepped up its operations against insurgents who have carried out almost daily attacks in Iraq.