Wednesday's blast in Mosul left at least 217 people wounded in addition to the fatalities, according to a provincial official.
"More than 100 houses were damaged," Hisham al-Hamdani, head of the provincial council of Ninawa, of which Mosul is the capital, was quoted by the AFP news agency as saying.
"Whole families have vanished. There are still people trapped under the rubble."
The explosion, in an unoccupied building used by fighters to store weapons and explosives, destroyed or badly damaged 35 nearby homes, the Reuters news agency reported.
Rescuers were still digging through the rubble on Thursday in search of survivors when a suicide bomber blew himself up next to Hasan and his bodyguards, the army said.
Brigadier-General Abdul Kareem al-Jubouri, head of operations in the Mosul police command, said Hasan died of his wounds while being rushed for emergency treatment.
One of Hasan's bodyguards and a policeman were also killed and another five wounded.
Police said an Iraqi journalist working for Xinhua, the Chinese state news agency, was among the wounded, although no more information was immediately available.
The US military said it was checking Iraqi media reports that a US soldier had also been wounded.
US commanders have identified Mosul, Iraq's third-largest city, as al-Qaeda's last major urban stronghold in Iraq, after its fighters were driven out of western Anbar province and from around Baghdad during security crackdowns last year.
Mosul officials earlier imposed an indefinite curfew after Wednesday's blast.