HONG KONG - Hong Kong authorities on Thursday urged thousands of pro-democracy protesters to immediately end their blockade of the city centre and said any attempt to occupy administrative buildings would be met with a resolute and firm response.
The mostly young protesters have demanded Hong Kong's leader, Leung Chun-ying, step down by the end of Thursday, threatening to occupy government buildings if he fails to do so.
They have also called on China to introduce full democracy so the city can freely choose its own leader.
Leung, appointed by Beijing, has refused to stand down, leaving the two sides far apart in a dispute over how much political control China should have over Hong Kong.
Steve Hui, senior superintendent of the Hong Kong police force, said police would take action in accordance with the law if the protesters tried to enter government buildings.
"Whenever there are violent and major incidents and crimes such as fighting and any other situation that jeopardises safety and public order, police will take resolute and firm action to restore public order," Hui said, when asked how police would respond should the students carry through with their threat.
"We assure that police will have enough manpower to deal with every single situation."
Riot police used tear gas, pepper spray and baton charges last weekend to quell unrest, the worst in Hong Kong since China resumed its rule of the former British colony in 1997.
The "Occupy Central" movement presents one of the biggest political challenges for Beijing since it violently crushed pro-democracy protests in Tiananmen Square in 1989.
Protesters across the city have dug in, setting up supply stations with water bottles, fruit, raincoats, towels, goggles, face masks, tents and umbrellas.
The Hong Kong Federation of Students, one of the protest organisers, has urged people to surround more government buildings from Friday unless the authorities accepted their demands.
Protest leaders addressed supporters camped near the government headquarters, preparing them for a potentially tense night ahead including the possibility of police using tear gas.
"In the coming days we will team up to support the movement and provide resources. We will fight until the very end," student leader Joshua Wong said from atop a ladder, to huge cheers.
The three main protest groups have started to work more closely together, trying to give a show of unity after some disagreements on tactics over the past several days.
The Hong Kong government said the protests, now in their sixth day, were affecting public order and public services.
"About 3,000 government officials will try their best tomorrow to return to work as (much) as possible. To maintain public service, the government headquarters must operate as usual," the government said in a statement.
"We urge the Occupy Central leaders and organisers to stop the movement immediately."
While the number of protesters on the streets fell on Thursday, the second of two-day public holiday, tension remained high and the demonstrations appeared far from over.
Outside Leung's office in the Central business district, protesters surrounded a police van that tried to enter the compound, prompting police to call reinforcements. Some protesters donned goggles and gas masks.
Earlier, about 100 protesters blocked the main road leading to Leung's office, some chanting, "Leung Chun-ying, Step Down!"