BEIRUT (REUTERS) - The Syrian army said an air strike late on Wednesday (April 12) by the United States-led coalition hit poison gas supplies belonging to the Islamic State in Iraq and Syria (ISIS) militant group, releasing a toxic substance that killed "hundreds", but the coalition denied carrying out raids in the area.

A statement by the army, flashed on Thursday by Syrian state TV, said the incident in the eastern Deir al-Zor province proved that ISIS and Al-Qaeda-linked militants "possess chemical weapons".

The report could not immediately be independently verified.

US Air Force Colonel John Dorrian, a spokesman for the coalition, said it had carried out no air strikes in that area at that time. "The Syrian claim is incorrect and likely intentional misinformation," he said in an email to Reuters.

The United States launched cruise missiles at a Syrian air base last week, in response to a deadly poison gas attack in the west of the country that Washington blamed on President Bashar al-Assad's government.

Syria and its ally Russia deny Damascus carried out any such chemical attack. Moscow has said the poison gas in that incident belonged to rebels.

The US strike on the Syrian air base was the first time Washington has deliberately and directly targeted the Syrian government. It is separately waging an air campaign against ISIS in eastern Syria.