Iraqi air force reportedly dropped hundreds of leaflets over the city of Mosul on Wednesday midnight, urging civilians to watch Isis and its bases for the Iraqi army, which will be liberating them soon.
Several social media users have circulated the copies of leaflets addressed to "the people of Mosul."
The Washington Post, citing Qais Karim of the Defence Ministry's media office, confirmed that the Iraqi air force's C-130 Hercules planes made the drop on Wednesday midnight to "mobilise the people" ahead of the Mosul op.
"Mosul is your city, Iraq is your Iraq," the flier read. "Your armed forces are very close to you. Watch their bases, record their infidel actions. Point out those who cooperate with them to destroy your ancient civilisation," it said.
"Your brothers in Salahuddin taught Isis a lesson, they won't forget. And so will you."
Iraq's defence minister Khalid al-Obeidi recently noted that the Sunni province of Anbar would be the key launching ground for the long-awaited operation to retake Mosul, the country's second-largest city, from the Islamic State.
Al Obeidi noted that for the Mosul op, it was important to "secure" Anbar.
Anbar, located west of Baghdad, was the first province to fall under Islamic State's control during the group's blitz last year.
The Iraqi forces recently also stopped its Tikrit offensive. "The battle to retake Tikrit will be difficult because of the preparations (ISIS) made," said Jawwad al-Etlebawi, spokesman for the Asaib Ahl al-Haq, a Shiite militia, told AFP.
"They planted bombs on all the streets, buildings, bridges, everything. For this reason, our forces were stopped by these defensive preparations."
In the meantime, local reports out of Mosul claim that Isis has already began its defensive move. A local media report noted that Isis is now securing the perimeters of the city, and in anticipation of an attack has dug up trenches all over the city .