Aljazeera has learned that the blast in the capital's al-Ghazaliya district on Sunday was so powerful that it destroyed three vehicles and killed the bomber.

A US military vehicle was also destroyed when an army patrol was ambushed in the al-Ani district north of Baghdad, according to Iraqi police.

Aljazeera also reports sporadic attacks around the country, killing at least eight Iraqi police officers, contractors and civilians to the west of Baghdad and in Mosul, Baiji and Ramadi.

Meanwhile, the Iraqi prime minister's spokesman, Laith Kuba, said that 90 fighters were killed and 178 arrested in the US military operations west of Iraq.

Kirkuk executions

An group linked to al-Qaida posted a video on the internet on Sunday showing the killing of two men it said were security guards captured in the northern oil centre of Kirkuk.
  
The two were seen being questioned and then shot to death in the footage by the Army of Ansar al-Sunna. The authenticity of the video could not be confirmed.
  
In a statement posted on the website, the group said the two were captured during "a battle lasting more than one hour between our mujahedin and guards in charge of protecting oil facilities" in Kirkuk, whose revenues "are used by Crusader forces to finance their operations in Iraq".
  
The battle, announced in a statement on Thursday, led to the killing of 10 guards, the Army of Ansar al-Sunna said.
  
"The ruling of God Almighty was carried out against the two prisoners after they confessed to working with the guards," it said, warning all those affiliated to "these repressive agencies" that they would meet the same fate unless they desisted.
  
The Army of Ansar al-Sunna regularly claims attacks against US and Iraqi government forces, as well as killings of foreign hostages and Iraqi "apostates".