this year face masks of Chinese President Xi Jinping

and Hong Kong's leader Carrie Lam

replaced the usual pumpkins and skeletons.

Halloween has long been a popular festival

in this Asian financial hub, but this year the holiday

has a new political significance.

In an attempt to quell almost five months of protests,

the government banned wearing masks in early October.

Hundreds of demonstrators wearing protest-themed mask

and costumes participated in an unauthorised march

through the city's financial district to a popular bar

district before police fired tear gas.

Around 200 protesters have been arrested so far

for violating the anti-mask law.

Hong Kong has plunged into its worst political crisis

in decades, triggered by a now withdrawn

controversial extradition bill.