Baghdad - At least 30 people were killed on Monday and another 68 were wounded when three suicide bombers blew themselves up one after another in a Baghdad market, media report said.

According to the Aswat al-Iraq news agency, the first attacker detonated a car bomb in the mostly Sunni neighborhood of Adhamiyah, and then, as people rushed to help the injured, two other attackers blew themselves up in the crowds.

Meanwhile, a 13-year-old female suicide bomber killed seven members of the tribal police in Iraq's Baquba city, witnesses told Deutsche Presse-Agentur dpa.

The bomber detonated herself in the midst of a checkpoint in al- Atibaa street in the centre of Baquba, 60 kilometres north of Baghdad.

Eight other people, including civilians and tribal police, were wounded in the attack.

Tribal police, also known as the Awakening Councils, are members of Sunni tribes who coordinated with the US forces to fight al-Qaeda militants in Iraq.

Diyala province and its capital Baquba have witnessed over 20 female suicide attacks during the last few months. In some of these instances, the female attackers, wearing black, head-to-toe clothing, have been able to infiltrate crowds unsuspected.

Women are beginning to be used to conduct suicide attacks in Iraq because they are less frequently subjected to body searches. Religious and cultural rules prevent predominantly-male security officers from touching women while conducting searches. (dpa)