BAGHDAD - A suspected al Qaida prisoner seized a gun during interrogation in Baghdad counter-terrorism detention center and shot dead three police officers and a policeman, an Interior Ministry source told Xinhua on Sunday.

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The incident occurred late on Saturday in Baghdad's central district if Karradah, when an inmate managed to seize the gun of a policeman and killed him before he shot dead Brigadier General Mu'yad, head of the counter-terrorism department, a Major and Lieutenant officers, the source told Xinhua on condition of anonymity.

The prisoner was also shot dead by the policemen in the center, the source said, adding that another prisoner was also wounded by the clash.

The incident came as the Iraqi security forces increased security alert in Baghdad and other Iraqi cities as they expect deadly attacks to be carried out by al-Qaida militants in retaliation for the killing of al-Qaida head Osama Bin Laden in Pakistan.

Violence and sporadic high-profile bomb attacks continue in the Iraqi cities despite the dramatic decrease of violence over the last three years.