Thousands of demonstrators moved to surround government buildings in Hong Kong Sunday night after a call for “new action” from protest leaders. They requested supporters of the pro-democracy Occupy Central or Umbrella Movement demonstration to gather in front of government buildings in the city’s Admiralty district, the Wall Street Journal reported.

The protest leaders had advised supporters in advance to bring with them umbrellas, goggles, helmets and masks, as well as food supplies, according to the Journal’s description of a post on the Facebook page of Scholarism, one of the student groups involved in organizing the protests.

And a Hong Wrong live stream of the demonstration indeed showed a mass of people holding umbrellas and wearing yellow hard hats and gas masks clashing with police dressed in riot gear. The police sprayed a solution that appeared to be pepper spray at individuals who were then arrested.

Multiple Twitter posts indicated protesters were seen at the Lung Wo Road tunnel bridge and near the government’s headquarters.

Police removed a number of demonstrators from their main protest site in Mong Kok Tuesday after a court injunction was issued against them. However, police began to clear areas of the site Wednesday, even though they were not covered by the injunction, displacing demonstrators from an area they had occupied for two months and apparently sparking the protest’s renewal Sunday.

Violent clashes followed the removal, and several demonstrators were hospitalized with head injuries after police hit them with batons, the South China Morning Post reported. The newspaper also said officers used a pepper spray-like solution to disperse protesters attempting to re-enter the site after being forced to leave.

“I think we have made it very clear that if [the police] continue the violent way of clearing up the place, we will have further actions,” Yvonne Leung, a leader of the Hong Kong Federation of Students, told local broadcaster RTHK. “The further actions include a possibility of some escalations pointed at government-related buildings or some of the government-related departments.”