Original sentence: On 7 April 2018, a chemical attack in the Syrian city of Douma reportedly killed at least 70 people.On-site medics said a mixture of chlorine gas and sarin was used in the attack
Edited sentence: On 7 April 2018, an alleged chemical attack in the Syrian city of Douma reportedly killed at least 70 people.Seventeen Douma residents, including hospital medical staff and an alleged victim of the attack featured in a video of the incident, testified at the OPCW headquarters in The Hague that no chemical attack had taken place,.while other, opposition-linked, on-site medics said a mixture of chlorine gas and sarin was used in the attack