Health officials say shelling killed 11 people on May 10 in the Iraqi city of Fallujah, which has been held by anti-government fighters since December.
Doctor Ahmed Shami of Fallujah's main hospital told the French news agency AFP that a further 20 people were wounded by the bombardment.
The latest casualties come a day after Iraqi forces launched a large-scale military operation to regain control of Fallujah, a predominantly Sunni city in Anbar Province west of Baghdad.
According to Iraq's Defense Ministry, government forces have killed many fighters from the Al-Qaeda-linked Islamic State of Iraq and the Levant, and confiscated a large amount of weapons and several vehicles.
Reports say mosques and houses were damaged during the operation.
More than 300 people, mostly civilians have been killed in Fallujah since the beginning of the year.
Based on reporting by AFP and CNN