Leaders of a Hong Kong pro-democracy movement kicked off a long-threatened mass civil disobedience protest early Sunday to challenge Beijing over its recent decision to rule out genuine democratic reforms for the former British colony.

Organizers of “Occupy Central with Love and Peace” said an “occupation” of the streets outside government headquarters has officially begun.

The movement had originally planned a mass sit-in to paralyze the Asian financial hub’s central business district Wednesday, but organizers made the surprise move in an apparent bid to harness momentum from a student-led demonstration outside the government complex that has attracted thousands of supporters over the past two nights.

Tens of thousands of people massed in the heart of Hong Kong late Saturday. The crowds swelled less than 24 hours after riot police used pepper spray to disperse protesters around government headquarters, arresting more than 60 people opposed to the Chinese government’s tightening grip on the city.

Saturday’s conflict came after demonstrators broke through a police cordon late Friday and scaled perimeter fences to invade the city’s main government compound in the culmination of a weeklong rally to demand free elections.

The Hospital Authority said 34 people had been treated by Saturday evening as a result of the clashes.

Pro-democracy supporters are demanding that China’s Communist leaders allow fully democratic elections in 2017.

China, which took control of the former British colony in 1997, has promised that Hong Kong’s top leader can be chosen through universal suffrage. But tensions over the Asian financial hub’s political future boiled over after China’s legislature last month ruled out letting the public nominate candidates, instead insisting they be screened by a committee of Beijing loyalists similar to the one that currently picks the city’s leader.

The organizers of the non-violent protest movement said they want Beijing to abandon its decision and the Hong Kong government to resume political reform consultations

“The courage of the students and members of the public in their spontaneous decision to stay has touched many Hong Kong people,” the group said in a statement. “Yet, the government has remained unmoved. As the wheel of time has reached this point, we have decided to arise and act.”

— Associated Press