Two protesters have been charged with violating Hong Kong's new ban on wearing masks at rallies. An 18-year-old student and a 38-year-old unemployed woman are the first to be prosecuted under the ban, which took effect on Saturday. Both have been released on bail, pending trial. The arrests follow a weekend of unrest, which saw clashes with police and widespread vandalism that crippled Hong Kong's train network. Metro rail services partially re-opened on Monday.