Hundreds of protesters rallied at Edinburgh Place in Hong Kong on Friday to denounce the use of tear gas against them.
A masked member of Citizen's Press Conference, a group representing protesters, said on stage that tear gas is "responsible for an incalculable damage to the health of Hongkongers."
"Meanwhile the regime refuses to release the chemical compositions of the toxic tear gas and its leftovers, making it difficult for doctors to treat patients. All this points to the necessity of more follow-up research on tear gas," he deplored, before urging the government "to stop deploying toxic gas immediately in future operations."
Protesters were seen with signs reading "Police wilfully obstruct emergency care to injured protesters and students by Paramedic First-Aiders" and "Stop tear gas." They later chanted "People in fear, city of tear."
Hong Kong has been rocked by protests sparked by the now-withdrawn extradition bill since March. The rallies have since evolved into a wider movement against the government, marked by violent clashes between protesters and the authorities.