BAGHDAD, May 17 (Xinhua) -- A total of 31 people were killed and 82 others wounded on Tuesday in three bomb attacks, including a suicide one, in Iraqi capital of Baghdad, security sources said.

One of the attacks occurred in Shaab district when a roadside bomb detonated at a crowded market and was followed by a massive explosion of a suicide bomber who blew up his explosive vest, leaving 15 people dead and 37 wounded, a police source told Xinhua on condition of anonymity.

Earlier, Saad Maan, the spokesman of Baghdad Operations Command (BOC), which is responsible for the security of Baghdad province, put the toll at 11 killed and 37 others wounded.

According to Maan, the suicide bomber apparently was a female in accordance with the remains of the attacker's body.

The attackers apparently followed the old tactic of first creating an initial explosion to attract security forces and people, and then setting off another blast to inflict heavier casualties.

Meanwhile, the Islamic State (IS) group claimed responsibility for the massive twin bomb explosions in Shaab district, saying that one of its suicide bombers hurled hand grenades on Shiite paramilitary members, known as Hashd Shaabi, at the marketplace before detonating his explosive vest, according to the statement, of which the authenticity could not be independently verified.

IS statement denied that the suicide bomber was a female.

Separately, a booby-trapped car detonated in Rasheed district in southern Baghdad, leaving five people killed and 10 others wounded, another police source told Xinhua on condition of anonymity.

The third attack occurred in the Shiite bastion of Sadr City district in eastern Baghdad, when a truck packed with explosives detonated at a wholesale market of Jamila, killing at least 11 people and wounding 35 others, the source added.

A week ago, Sadr City was the scene of a deadly bomb attack, which also claimed by IS group, that left some 64 people killed and some 87 others wounded.

Iraqi security forces intensified security measures across the capital as intelligence reports said that more car bombs could hit the city during the coming few hours, the source said.