Fire swept through an indoor market in east Mosul on Sunday after what witnesses described as mortar rounds hit several stalls.
At least two people were killed and many others were injured in the busy Nabi Younis market.
East Mosul was declared liberated by the Iraqi government earlier this year with locals resuming some normality of life after ISIL fighters were ousted.
In west Mosul where the battle for control is still raging, it is unclear which side was responsible for possibly as many as 200 civilian deaths in an explosion a week ago.
Initially a US-led coalition strike against so-called Islamic State snipers was said to have caused buildings to collapse in the Jadida district. However, Iraq’s military has cast doubt on that report claiming 61 bodies had been recovered and that explosive booby-traps set by the jihadists were responsible for the destruction of the buildings.
The US said on Saturday (March 25) that it was investigating an air strike on March 17 at “the location corresponding to allegations of civilian casualties”.
According to a monitoring group, nearly 700 civilians have died since the offensive in west Mosul began last month. Hundreds more are said to flee each day.