HONG KONG—A dozen Hong Kong pro-democracy activists pleaded guilty Thursday to participating in an unauthorized candlelight vigil to mark Beijing’s bloody crackdown in Tiananmen Square. The 12 were charged with participating in the unauthorized assembly in Victoria Park on June 4 last year, when thousands of Hong Kongers turned up to light candles and sing songs despite police warnings that they may be breaking the law. Seven of the 12 were also charged with inciting others to take part in the assembly. Authorities have banned the vigils for the past two years, citing public health risks due to the pandemic, although critics believe the ban is part of an ongoing crackdown on dissent following months of protests against the regime in 2019. Prior to the ban, the candlelight vigil event held on June 4 every year was attended by massive crowds and was the only large-scale public commemoration on Chinese …