Dr. Wahid Majroh, spokesman for the Ministry of Public Health, said 31 dead and 54 injured individuals had been evacuated to hospitals from the blast site.
But, an eyewitness, Mohammad Amin, said dozens of people were killed and wounded in the suicide attack. According to another eyewitness, about 30 people have been killed.
The huge explosion echoed across the city, shattering windows miles away from the site and damaging several nearby vehicles. Police blocked all roads to the site, with only ambulances allowed in.
There was no immediate claim of responsibility for the blast.