Doctors and medics in the rebel-held enclave of Eastern Ghouta near the Syrian Capital Damascus on Tuesday reported a suspected chlorine attack, BBC reported. They said they were treating people with breathing problems.

The reports emerged following the airstrikes and shelling that the government of President Bashar al-Assad allegedly carried out, just a few hours after the last United Nations aid convoy left the enclave.

The group of search and rescue workers called the White Helmets tweeted that 30 cases of suffocation had been reported after the attack in Hamorieh city.

The Syrian Observatory for Human Rights said that at least 70 people had been killed in the airstrikes, Al Jazeera reported. The UN Human Rights Council on Monday had ordered a “comprehensive and independent” investigation into the recent violence in the rebel-held area, and condemned the alleged use of chemical weapons.

The fighting has continued despite Russian President Vladimir Putin’s order to implement a daily five-hour ceasefire in the region. France and the United States had urged Russia on March 1 to exert pressure on Syria to implement a resolution that the United Nations passed in January for a 30-day ceasefire.