Four Turkish soldiers were killed Wednesday in a car bombing in northeastern Syria, Turkey's defence ministry said.
The soldiers were conducting road patrols when the attack happened in the region captured by Turkish forces after the latest operation against a Kurdish militia last year.
The ministry did not provide further information on exactly where the bomb exploded or who was to blame for the attack.
Turkish soldiers supporting Syrian proxies launched an offensive against the US-backed Syrian Kurdish People's Protection Units (YPG) militia in October 2019.
Ankara says the YPG is a "terrorist" offshoot of the outlawed Kurdistan Workers' Party (PKK), which has waged an insurgency against the Turkish state since 1984.
The PKK is blacklisted as a terror group by Turkey and its Western allies.
Turkey previously launched two military operations in northern Syria against the Islamic State extremist group in 2016 and the YPG in 2018.