MARK KERRISON | Photojournalist

London, UK. 5 October, 2019. Activists from Democracy for Hong Kong protest in Trafalgar Square against the invocation by Hong Kong's leader Carrie Lam of emergency powers last used in 1967 under the 1922 Emergency Regulations Ordinance to ban people other than those using them for religious, medical or professional purposes from covering their faces, wearing face masks or using paint on their faces during public assemblies, be they authorised or unauthorised protests or public processions. Breaches of these powers carry penalties of up to one year in prison and a fine of HKD 25,000. The prohibition came into effect today and has led to further demonstrations in Hong Kong. This is the 18th weekend of anti-government demonstrations in Hong Kong. Most demonstrators wear masks in order to disguise their identity and some wear gas masks and respirators to protect against tear gas used by the police. Hong Kong police, who have used tear gas, rubber bullets, water cannon and live ammunition to respond to the anti-government demonstrations, have been widely criticised for their tactics and are extremely unpopular with the demonstrators.