HONG KONG — Tens of thousands of pro-democracy activists turned out in Hong Kong Monday to commemorate the 29th anniversary of the Tiananmen Square crackdown in Beijing, observing an event that goes largely unmentioned in mainland China.

This year’s vigil focused on freeing “dissidents imprisoned or under home arrest” in addition to pushing for greater democracy in mainland China.

The protesters marking the Tiananmen anniversary in Hong Kong have seen their numbers dwindle in the years since the Occupy Central pro-democracy movement gripped Hong Kong in 2014. Organizers said as many as 180,000 people showed up to that year’s June 4 vigil — the police estimated the number to be roughly half that — but last year they estimated 110,000 people attended.

Heavy rains on Monday also limited this year’s turnout at the event, held annually in the semiautonomous territory.