ISTANBUL – A Turkish military The convoy was hit on Monday by an air raid in Syria that killed three civilians, the Turkish Ministry of Defense said in a statement.
Syria's government said the convoy contained weapons intended for insurgents without telling them whether it was behind the strike in Idlib province.
The attack threatened to trigger a new round of violence between the governments of Syria and Turkey, jeopardizing the fragile military cooperation between Moscow and Ankara in northern Syria, including agreements aimed at reducing violence there.
While Turkey was able to maintain observation posts in Idlib, cooperation with Russia has not prevented the government of President Bashar al-Assad, Russia's ally, from undertaking an all-out offensive to recapture the province continue from Syrian rebel groups.
Turkey has not said who carried out the air strike, but at least partially accused Russia.
The Russian government had received "advance information" on the route of the convoy, the ministry said. The attack "contradicts existing agreements, cooperation and dialogue with the Russian Federation" and called for "all necessary measures to prevent the recurrence of such incidents".
Turkey has maintained its right to self-defense, the statement said. The convoy left on Monday at 5.30 clock to the Turkish observation post and was attacked shortly before 9:00 clock from the air. In addition to the three dead, 12 civilians were wounded.
The Syrian government said in a separate statement that the convoy had been loaded with "ammunition, weapons and supplies" destined for a Syrian jihadist group in Khan Sheikhoun, a target of the government's offensive and one of the last major rebel redoubts. It called the convoy "a grave violation of the sovereignty and territorial integrity of the Syrian Arab Republic".
The Russian-backed Idlib offensive in Syria has killed hundreds of civilians and displaced hundreds of thousands of people since April, fueling fears of another refugee move from Syria, according to UN officials. Turkish President Recep Tayyip Erdogan, a long-time supporter of the Syrian opposition, did not seem to blunt the offensive despite his ever-closer partnership with Russian President Vladimir Putin.
These relations have become even warmer in recent weeks after Turkey overtook the Trump government's objections to a progressive Russian air defense system.
But in Idlib a series of truces has collapsed, including a deal in early August. The Syrian government has accused the rebels of failing to comply with the terms of an agreement between Turkey and Russia to de-escalate violence in the province. According to activists, a flood of air strikes has killed dozens of civilians throughout Idlib in recent days.
Turkey has previously avenged itself after accusing Syria of having made lethal attacks on Turkish military personnel in Idlib. In June, Turkey fired heavy weapons into Syrian territory after a Turkish soldier was killed in Ankara during a Syrian attack.
Liz Sly contributed to this report from Beirut.