One police official said the attack took place at around 9:30 a.m. (0530 GMT) in a market that was full of shoppers.

Another official said the bomb had been made of gas canisters and hidden near a road to the market.

Witnesses at the scene said that the blast took place near the crowded market and brought down the power cables, setting part ofthe market ablaze.

Kirkuk, a city claimed by three ethnic groups -- Kurds, Turkmenand Arabs -- has suffered persistent unrest in recent months.

Source: Xinhua