Iraqi government forces and Islamic State militants continued their stand-off in the northern city of Tikrit on Sunday.
Since early March, Iraqi troops have been intensifying their military campaign to retake the major city. They now have about 60 percent of Tikrit under their control.
The militants are holed in the central districts. They have set up ambushes by planting bombs in many parts of the city to keep the government forces away.
State media say the Iraqi military has sent in reinforcements, including a bomb squad, to try to minimize the damage to civilians and troops.
Meanwhile, officials of the Kurdish autonomous government in Iraq have accused the Islamic State militants of using toxic chlorine gas outside of Iraq's second-largest city, Mosul, in January.
Kurdish Minister in charge of Foreign Relations Falah Mustafa said in an interview with NHK on Sunday that the use of a chemical weapon by the terrorist group was expected, but it reconfirms the needs for the international cooperation.
