"Our companions were killed in a vile and infamous attack," said Turkish Defence Minister Hulusi Akar, while the presidency vowed to avenge the killings.

The attackers targeted "a unit returning from a patrol", the ministry said, without giving details on the type of assault.

An AFP reporter on the scene said it was a bomb blast on the Idlib-Bennish road.

Idlib is home to the last major jihadist and rebel stronghold in northwest Syria.

Offering his condolences to the families of the dead soldiers, Turkish presidency spokesman Ibrahim Kalin said on Twitter that "none of our martyrs will go unavenged".

Echoing that sentiment Akra said that, "The blood shed by our martyrs has never gone unpunished and will not go unpunished this time."

Akar, accompanied by military generals, visited the injured soldiers who were transferred to a hospital in the southern Turkish town of Hatay.

After several successive offensives by government forces, a ceasefire was negotiated with the Syrian regime, but some groups have rejected this agreement.

The truce, brokered by neighbouring Turkey -- which backs some rebel groups -- and Syrian regime ally Russia, has largely been in force since March 2020, despite sporadic clashes.