A footage by a Russian television channel circulated on Sunday showed deployment of additional armored vehicles and strengthening of firing positions by the Turkish military near the town of Tell Abyad.
"We consider these actions as provocative acts that could derail the ceasefire regime and the entire reconciliation process in Syria," Lt. Gen. Sergei Kuralenko told reporters at the Hmeimim airbase near Latakia.
Turkey has also been shelling other towns in northern Syria, claiming that the Syrian Kurds have links to the Kurdistan Workers' Party (PKK), which is fighting for Kurdish independence from Turkey and is considered a terrorist organization by Ankara.
Russia and the United States reached an agreement on the ceasefire in Syria on February 22. The ceasefire took effect at midnight on Saturday Damascus time.
The UN Security Council unanimously adopted Resolution 2268 endorsing the Russia-US agreement on the cessation of hostilities in Syria on Friday, shortly before the ceasefire came into force. The cessation of hostilities does not apply to designated terrorist organizations operating in Syria, including IS and the Nusra Front, both outlawed in Russia.