The Iraqi army, federal police and counter-terrorism forces, backed by 20,000 fighters from the predominantly Shia and Iranian-backed Hashed al-Shaabi paramilitary group, launched the offensive on Tal Afar.
On Saturday, Iraq's War Media Cell urged the citizens in areas surrounding Tal Afar to tune in to 104.5 FM in order to receive information.
The US-backed coalition reportedly needs significant resupplying and repairing before carrying out the operation to take back Tal Afar.
An AFP correspondent reported mortar fire in the mostly desert area dotted by some farmland, with columns of smoke billowing skywards.
About 2,000 battle-hardened militants remain in Tal Afar, according to US and Iraqi military commanders.
He finished his speech with an address to Iraqi troops: "The whole world is with you".
"Mosul was a decisive victory for the Iraqi Security Forces, but it did not mark the end of [IS] in Iraq, or its worldwide threat", said US Army Lieutenant General Stephen Townsend, the commander of US and Coalition forces in Iraq and Syria. "He's going to be facing a determined ISIS fighter dug into Tal Afar, determined to fight to the death", he added.
All these forces were backed by the Iraqi Air Force and the US-led worldwide coalition.
Tal Afar s Shiites were directly targeted by IS, while some members of its Sunni minority joined the jihadists and went on to form a contingent with a particularly brutal reputation.More news: OnePlus 5 Slate Gray 8GB, 128GB variant goes on sale in India
Anti-IS coalition forces estimate that between 50,000 and 100,000 civilians remain in and around the city.
Un Humanitarian Coordinator for Iraq Lisa Grande said Sunday that "more than 30,000 people have already fled" the Tal Afar region and that thousands more were expected to seek to flee.
"Families are trekking for 10 to 20 hours in extreme heat to reach mustering points", she said. "They are arriving exhausted and dehydrated", Grande said in a statement.
When Daesh captured Tal Afar, the population was estimated at around 200,000 and was overwhelmingly Turkmen, one of Iraq's largest ethnic minorities.
"In the early hours, the guns and flags turned towards their targets", said Hashed spokesman Ahmed al-Assadi.
Only one part of Tal Afar, Sarai, is comparable to Mosul's Old City, where Iraqi troops were forced to advance on foot through narrow streets moving house-to-house in a battle that resulted in the near total destruction of the historic district.
The Iraqi air force dropped leaflets over the city warning people to "prepare" for the latest assault.
Iraqi authorities have set up a toll-free number and a radio station to help guide fleeing civilians to safety.
USA forces have been working with Iraq's military since October 2014 to help Iraq retake territory from the Islamic State, an al-Qaeda offshoot that swept across eastern Syria and much of western Iraq earlier that year.