Syrian army's statement came almost a week after the opposition accused the Syrian government air force of firing toxic gas on the rebel-held town of Khan Sheikhoun in Idlib province. (Reuters photo)

DAMASCUS, April 13 (Xinhua) -- The Syrian army on Thursday said the U.S.-led anti-terror coalition struck a chemical weapons depot controlled by the Islamic State (IS) group in eastern Syria, killing hundreds, including civilians.

The U.S.-led airstrikes targeted the big depot containing chemical materials in the town of Hatleh in the eastern countryside of Deir al-Zour on Wednesday, said the army in a statement.

It added that large numbers of civilians were among those killed due to the suffocation caused by the spread of the toxic materials.

The explosion of the arm depot left a big white cloud, which turned into yellow, said the statement.

"This incident is a sign of the coordination between the terrorist groups and the powers supporting them to find pretexts to frame the Syrian army and accuse it of using chemical weapons," the statement said, almost a week after the opposition accused the Syrian government air force of firing toxic gas on the rebel-held town of Khan Sheikhoun in Idlib province.

At the time, the Syrian government rejected the accusations, blaming the rebels of storing chemical materials in the targeted area.

The U.S. was quick to accuse the government, launching a missile strike against Syria's largest airbase, causing damages and killing six soldiers and nine civilians.

This time, the military statement said that the terrorist groups, including IS and the al-Qaida-linked Nusra Front are in possession of chemical weapons.

"The terrorist groups are capable of obtaining, and stockpiling such weapons with the help of well-known regional countries and that what Syria has been warning against in every instance the rebels used chemical weapons against civilians and government forces," the statement said.