Iraqi troops and militia fighters attacked Islamic State militants in a key area north of Baghdad Monday, the first full day of a highly publicized offensive to recapture the city of Tikrit.
Ground troops advanced on multiple fronts with support from airstrikes, military commanders said. The operation includes an estimated 30,000 members of Iraq's military, Shi'ite militias and Kurdish peshmerga fighters.
The assault is a key test for the struggling Iraqi army. And in what may be an indication of a long fight ahead, hours into the operation the military still hadn't entered the city, a commander told The Associated Press.
General Abdul-Wahab al-Saadi, commander for the province, told state TV the operation was "going on as planned," with fighting taking place outside Tikrit, mainly on its eastern side, the AP reported.
State-run Al-Iraqiya television said the militants had left some areas outside the city, but gave no more details of the fighting.
In footage aired on Iranian television, a member of Iraq's forces held up an ammunition belt and said he is prepared to "crush" the Islamic State militants, who overran the hometown of executed leader Saddam Hussein last year.
The military offensive is the largest since the Islamic State group took control of Tikrit last June, when the militants took control of large swathes of northern Iraq, as well as parts of eastern Syria. That land grab also netted them Mosul, Iraq's second largest city, located just north of Tikrit's province.
Iraqi Prime Minister Haider al-Abadi issued an ultimatum at the start of the operation Sunday, offering what he called "the last chance" for Islamic State supporters to be pardoned if they defected from the group.
"I call upon those who have been misled or committed a mistake to lay down arms and join their people and security forces in order to liberate their cities,'' Abadi said.
Abadi and Nickolay Mladenov, the U.N. special envoy in Iraq, both appealed to warring groups to avoid attacking civilians.
A victory in Tikrit would be a geographic stepping-stone for Iraqi forces to approach Mosul -- a stronghold and nerve-center for the Islamic State group.
Before Monday's offensive, Iraqi forces tried, and failed, several times to retake Tikrit, the provincial capital of Salauhddin province, about 130 kilometers (80 miles) north of Baghdad.
However, in the past few months Iraq has made some strides in pushing back Islamic State fighters from near Baghdad, in the Kurdish north, and in the eastern province of Diyala. Iraq's military has had support from U.S.-led airstrikes in Iraq, as well as by combining forces with Shi'ite militias and Kurdish peshmerga fighters.
A senior U.S. defense official confirmed to VOA last month that Shi'ite forces were organizing a battle for Tikrit, but did not say when the offensive would take place.
A U.S. Central Command official also said last month that Iraqi forces and Kurdish fighters were planning to launch an offensive to recapture Mosul in April or May.
Some material for this report came from Reuters, AP and AFP.