This rebel drone video shows the extent of damages incurred during the offensive.
Turkey is backing a group of Syrian rebels, mainly Arab and Turkmen, in northern Syria against Islamic State and hopes to stop the advance of the YPG, which it sees as a hostile force.
Dozens of Turkish soldiers were killed supporting Syrian rebels in the fight for Al Bab as the extremists put up fierce resistance, including the use of suicide bombers.
An official with the Fastaqim rebel group told Reuters that all strategic areas of the town had been seized but that street fighting continued.
"More than half of the town is now in our hands", he said, indicating that the operation to surround Al-Bab was "over" with troops now moving from district-to-district to "clean up" the town.
Ahmad Othman, a rebel commander, told Anadolu: "We are announcing Al-Bab completely liberated, and we are now clearing mines from the residential areas".
"We estimate there are less than 100" Daesh fighters left in Al-Bab, Isik told NTV.
"Yesterday (Wednesday), we captured the city centre, which was IS's security zone".
Anadolu reported that 44 IS fighters were killed, 15 in battles with Turkish forces, and 29 in air strikes carried out by the US-led global coalition, also joined by Turkey.
On Aug. 24, 2016, the Turkish Armed Force launched an operation to liberate the city of Jarabulus from the IS militants in northern Syria, near Aleppo.
The resident and regional UN humanitarian coordinators for Syria said in a joint statement that the United Nations was "deeply concerned" over the fate of some 5,000 civilians trapped in and around Al-Bab as the fighting continues. They also said Turkish forces "neutralized" 306 Kurdish YPG fighters, killing 291 of them, the ministry added.