ISIS made an agreement with PKK/PYD to withdraw from Raqqa -- its former stronghold in Syria -- without armed conflict, Russian Foreign Minister Sergey Lavrov said Wednesday.

Axar.az reports citing Anadolu news.

Lavrov said Russia's Defense Ministry confirmed the information, although the PKK/PYD terror group rejected it.

"Soon after this information was made public, ISIS militants exited Raqqa and moved towards Palmyra," Lavrov told reporters in Moscow.

"As you know, Russian air forces spotted this movement and attacked this convoy," he said.

Russia will remain committed to fighting ISIS on Syrian soil, Lavrov added.

According to the Russian TASS news agency, a source in Russia’s Defense Ministry said on Saturday the two terrorist organizations reached an agreement on opening a safe southern corridor for ISIS terrorists towards Palmyra.

On Tuesday, Russia forces reportedly hit ISIS targets east of Palmyra as they moved out of Raqqa.

Last Friday, the U.S.-backed SDF, which contains numerous elements linked to the terrorist PKK/PYD group, called on ISIS militants in Raqqa to surrender by the end of the current month.

Since then, air and artillery attacks on the city -- by the U.S.-led coalition and the SDF respectively -- have intensified, resulting in scores of civilian casualties.