Turkish armed forces and allied Syrian fighters have seized near full control of the key town of Al Bab in northern Syria from ISIL, according to multiple sources.

Al-Bab, just 25km south of the Turkish border, has been the target of an over three-month assault by Turkey and rebel forces which met with fierce resistance by ISIL fighters, who had captured the Aleppo province town in early 2014.

"It's been a long time since we came to Al Bab but today we can say that near complete control has been taken of Al Bab and the city centre has been entered," Turkish Defence Minister Fikri Isik said on Thursday, quoted by the state-run Anadolu news agency.

Earlier, Anadolu said fighters from the Free Syrian Army (FSA) group were clearing mines and explosives devices laid by the Islamic State of Iraq and the Levant (ISIL) group after capturing the centre of the flashpoint town.

READ MORE: Turkish army will press on to ISIL-held Raqqa, says Erdogan

"Most of al-Bab has been liberated," an FSA commander, speaking on condition of anonymity, also told Al Jazeera.

He said the advance in the city had been slowed down because of ISIL's booby traps and suicide bombings, some of which had been carried out by children as young as 13 years old.

However, the Syrian Observatory for Human Rights, a UK-based monitoring group tracking developments in Syria's conflict, said that more than half of Al Bab was still under ISIL control, and that battles continued.

'Risky work ahead'

Al Jazeera's Andrew Simmons, reporting from the Turkish city of Gaziantep near the border with Syria, quoted Turkish defence officials as saying that rebel forces were still facing "a lot of risky work ahead", clearing mines and improvised explosive devices, as well as dealing with possible counterattacks.

He also reported that FSA fighters are now trying to move into smaller villages near Al Bab.

"This is undoubtedly an important milestone that Turkey can now claim in its mission into Syria, its fight against ISIL and attempt to push back Kurdish-led forces," Simmons said.

"Now word is awaited from the US on whether Turkey and the FSA can join in the fight in Raqqa [ISIL's self-declared capital in Syria]."

Turkey launched its Syrian operation Operation Euphrates Shield in August, in an effort to push ISIL from its border and stop the advance of a Syrian Kurdish militia.

Backed by Turkish fighter jets, tanks and special forces, the FSA fighters first cleared ISIL from Turkey's border before launching an assault on Al Bab in December.

A total of 1,900 square kilometres in northern Syria has now been cleared of armed groups, Anadolu said.

While Euphrates Shield has been largely focused so far on combating ISIL, Ankara is also determined to prevent the Kurdish YPG militia, which it considers a "terrorist" group, from linking the areas it controls along the Turkish border.

Earlier in February, Turkey's President Recep Tayyip Erdogan said the final goal of the Turkish incursion into northern Syria is to clear a 5,000sq-km "safe zone", vowing to press on towards Raqqa.

The FSA commander on Thursday told Al Jazeera that after Al Bab is secured the forces will then proceed to Raqqa, adding that a military operation against ISIL fighters in Manbij is not as likely.

Abd al-Majed Barakat, political adviser to the Operation Euphrates Shield, told Al Jazeera the operation has the capacity to lead the Raqqa offensive but needs the support of an international coalition, adding that he new US administration has not made clear its plans on Syria.

FSA troops are being trained and prepared in camps on the Turkish-Syrian border north of Raqqa and Hassaka provinces for the operation on ISIL's stronghold, he said.

Additional reporting by Mariya Petkova.