All 12 reported killed were Asians or Arabs, said the head of Qatar's police force Maj Gen Saad al-Khulaifi, adding some of the injured were seriously hurt. Initial indications suggested a burst natural gas tank on top of a Turkish restaurant was to blame for the explosion, BBC reported.
The incident occurred shortly after 10.00 a.m. (7:00 GMT), near a petrol station and the popular Landmark Mall shopping centre. The force of the blast caused the partial collapse of the Istanbul Restaurant. It also sent shrapnel flying up to 50m (160ft) away, authorities said.
Though officials were treating the explosion as an accident, though it was unclear what ignited the tank, the report added.
"We do not have any information about whether Indians are among the victims," an Indian embassy official in Doha told IANS.
Qatar, also a home to around 600,000 expatriate Indians, many of them blue collar workers, is a small, wealthy Gulf Arab state with abundant reserves of natural gas and little violent crime or civil unrest, although concerns have been raised about building safety.