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BAGHDAD, Nov 29 (Reuters) - Iraqi security forces detonated two car bombs inside the compound of the head of the main Sunni Arab bloc on Thursday, a security official said, but the politician insisted they were discovered outside the complex.

No one was hurt in the incident, which could inflame tensions between the Sunni Accordance Front and the Shi'ite-led administration of Prime Minister Nuri al-Maliki.

Baghdad security spokesman Brigadier-General Qassim Moussawi did not accuse Adnan al-Dulaimi or his staff of having any links to the car bombs but said an investigation would be launched into how the vehicles came to be in the yard.

Six of Dulaimi's guards had been detained, he told Reuters.

He said the bombs were found inside the compound when security forces chased a suspected fugitive involved in a separate shooting incident into the yard. Moussawi said the detonations damaged the office in west Baghdad.

Dulaimi, the leader of the Accordance Front, which quit Maliki's government in August, insisted the bombs were found nearby.

"The cars were not detonated (in) the office, but on a side street behind the compound. The security forces should have towed the cars away (because the explosion) burned nearby houses," Dulaimi told Reuters by telephone.

A spokesman for Dulaimi said the office was not damaged. Iraqi and U.S. forces had detained 12 of Dulaimi's security detail, he added. The U.S. military had no immediate comment.

Moussawi, speaking on Iraqi state television, repeated his account of what happened.

"There is an investigation into how the cars got into Dr Adnan al-Dulaimi's office. There is no immunity from the law," he added without elaborating.

The Accordance Front has said it will not return to the cabinet unless Maliki meets demands such as giving the bloc a greater say in security matters and releasing detainees picked up in security operations.

The vast majority of detainees in Iraqi and U.S. prison camps are Sunni Arabs accused of involvement in attacks against Iraqi and U.S. security forces. (Reporting by Wissam Mohammed, Waleed Ibrahim and Alaa Shahine, Writing by Dean Yates; Editing by Charles Dick)

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