Citing their correspondent in Idlib, news agency Anadolu said the withdrawal was concluded under a deal reached last month between Syrian regime ally Moscow and rebel backer Ankara.
Turkey-backed Syrian opposition forces as well as anti-regime armed groups pulled out heavy weapons, including rocket launchers, mortars and medium-range missiles, Anadolu added.
Turkish President Recep Tayyip Erdogan and Russian counterpart Vladimir Putin agreed on September 17 to establish a demilitarized zone in Idlib.
The accord aims to stave off a massive regime assault on Idlib province by creating a 15 to 20-kilometer (9-12 mile) buffer zone ringing the area.
All rebels in the demilitarized zone must withdraw heavy arms by Wednesday, and radical groups must leave by October 15, under the deal.
The National Liberation Front (NLF), the main Turkey-backed rebel alliance in the Idlib area, announced Saturday it had begun withdrawing heavy arms as part of the agreement and the withdrawal would take several days.
Idlib is widely regarded as the last major province Assad needs to take over in order to have won the war, although several areas across Syria are still not under his control.
The US led coalition is still fighting a fierce battle against Islamic State (IS) in the north eastern part of Syria, and to the north Turkey is controlling large parts, refusing to leave before the Syrian people have held an election.
The Syrian Kurds are also fighting to control its own territory in the area near the Turkish border, raising the prospects of a long battle for control of land.
Turkey considers the Syrian Kurds terrorists due to their deep ties to the Kurdistan Workers’ Party, also known as the P.K.K, a long time rival of President Erdogan.
The Syrian war has left more than 360,000 people dead since it began in 2011 with the repression of anti-government protests.