Baghdad, September 27 (RHC/Xinhua) -- The Islamic State (IS) group on Tuesday claimed responsibility for two suicide bomb attacks at busy commercial areas in the Iraqi capital of Baghdad that killed a total of 15 people and wounded 59 others, the group said in an on-line statement.

One of the group's suicide bombers detonated his explosive vest in a crowd of Shiite people in eastern Baghdad, while another suicide bomber struck Baiyaa district in southern Baghdad, according to a brief statement, of which the authenticity could not be independently verified.

Following the two attacks, Baghdad authorities intensified security measures in checkpoints across the capital, and blocked several neighborhoods for fear of further attacks.

Terrorist acts, violence and armed conflicts killed 691 Iraqis and wounded 1,016 others in August across Iraq, the United Nations Assistance Mission for Iraq said earlier.

Analysts blame the current chronic instability, cycle of violence, and the emergence of extremist groups, such as the Islamic State, on the United States, which invaded and occupied Iraq in March 2003.