On 7 April 2018, a chemical attack was carried out in the city. Douma had been the target of four reported chemical attacks over four months in 2018, as pro-government forces intensified their aerial bombardment before launching a ground offensive. The last and deadliest, according to medics and rescue workers occurred when a yellow industrial gas cylinder was reportedly dropped onto the balcony of a block of flats. The opposition's surrender came a day later. In September 2018, the UN Commission of Enquiry on Syria reported: "Throughout 7 April, numerous aerial attacks were carried out in Douma, striking various residential areas. A vast body of evidence collected by the Commission suggests that, at approximately 7.30 p.m., a gas cylinder containing a chlorine payload delivered by helicopter struck a multi-storey residential apartment building located approximately 100 metres south-west of Shohada square. The Commission received information on the death of at least 49 individuals, and the wounding of up to 650 others... the Commission cannot make yet any conclusions concerning the exact causes of death, in particular on whether another agent was used in addition to chlorine that may have caused or contributed to deaths and injuries" Local rebels and civilians were sent into northern Syria in forced exile. Similar forced displacement deals have taken place all over Syria.