MOSCOW, Nov. 15 (Xinhua) -- The U.S.-led coalition in Syria has resumed intensive air strikes in the terrorist-held localities in the regions east of the Euphrates, Russia Foreign Ministry spokeswoman Maria Zakharova said Thursday, quoting local Syrian residents.

She said white phosphorus bombs were used in the "non-selective" strikes, which killed and injured more than 60 civilians in the village of al-Shafa in the eastern Syrian Deir ez-Zor province.

The Syrian Foreign Ministry sent two letters to the UN secretary-general and the chairman of the UN Security Council in this regard demanding an end to these attacks and an investigation in them, as well as punishment for the perpetrators, Zakharova said.

White phosphorus is an incendiary and toxic chemical substance used as a filler of various munitions, the use of which for incendiary purposes is prohibited by the 1980 Convention on Certain Conventional Weapons.

Its use as a toxic agent in munitions is banned under the 1992 Chemical Weapons Convention.