Student leaders of Hong Kong’s pro-democracy protests warned that if the territory’s top official doesn’t resign by Thursday they will step up their actions, including occupying several important government buildings.

By raising the stakes in the standoff, the protesters are risking another round of confrontation with police, who are unlikely to allow government buildings to be stormed. It also puts pressure on the Chinese government, which so far has said little beyond declaring the protests illegal and backing Hong Kong Chief Executive Leung Chun-ying’s attempts to end them.

But Chinese state media indicated that the central government may be losing patience with the protests, and urged support for decisive action to end them.

An editorial solemnly read on China’s main TV broadcaster CCTV said all Hong Kong residents should support authorities to “deploy police enforcement decisively” and “restore the social order in Hong Kong as soon as possible.”

The student leaders have played a key role in organizing the protests to press for greater electoral reforms. The demonstrations pose the stiffest challenge to Beijing’s authority since China took control of the former British colony in 1997.

Lester Shum, vice secretary of the Hong Kong Federation of Students, said the students would welcome an opportunity to speak to a Chinese central government official.

“However, we ask them to come to the square and speak to the masses,” Shum told reporters. “This is a movement of Hong Kongers and not led by any specific group.”

Shum demanded that Leung resign by the end of Thursday. He said there was “no room for dialogue” with Leung because he had ordered police to fire tear gas at protesters over the weekend.

“Leung Chun-ying must step down. If he doesn’t resign by tomorrow we will step up our actions, such as by occupying several important government buildings,” he said, adding that demonstrators would not interfere with “essential” government agencies, such as hospitals and social welfare offices.

The protesters oppose Beijing’s decision in August that all candidates in an inaugural 2017 election for the territory’s top post must be approved by a committee of mostly pro-Beijing local elites. They say China is reneging on a promise that the chief executive would be chosen through “universal suffrage.”

Earlier Wednesday, protesters heckled Leung as he attended a flag-raising ceremony marking China’s National Day, the day Communist China was founded in 1949. Hundreds yelled at him to step down, then fell silent and turned their backs when the ceremony began.

In a speech, Leung made no direct mention of the protesters, but told voters it is better to agree to Beijing’s plan for vetting candidates and hold an election, than to stick with the current system in which an Election Commission chooses the chief executive.

President Xi Jinping, who has taken a hard line against any perceived threats to the Communist Party’s hold on power, vowed in a National Day speech to “steadfastly safeguard” Hong Kong’s prosperity and stability.

An editorial in the Communist Party-run People’s Daily warned of “unimaginable consequences” if the protests are left unchecked.

“They have already severely disrupted the normal life of the Hong Kong public, and even endangered the property and personal safety of the Hong Kong public,” it said.

Protest numbers swelled on Wednesday, a national holiday, to tens of thousands, including many families with children, couples, students, retirees and foreigners who live in the city of 7 million. Many thronged a six-lane highway in front of the government headquarters in the Admiralty area, while others gathered in the downtown areas of Causeway Bay and Mong Kok.

“I came out today to support the movement. No student leaders or occupy leaders urged me to come out. I came out on my own,” said Pierre Wong, a 36-year-old IT technician. “I hope there will be democratic reform, instead of using the current framework.”

Throughout the protest zones, volunteers manned supply stations, handing out water, crackers, umbrellas, rain coats and plastic wrap — which was also used to protect against the pepper spray and tear gas used by police over the weekend.

The growing protests have attracted worldwide attention, with British Prime Minister David Cameron saying he planned to summon the Chinese ambassador to discuss the standoff, saying it is essential that Hong Kong’s people have a genuine right to choose their leader.

“It is not for us to involve ourselves in every dot and comma of what the Chinese set out,” Cameron said in England. But he added, “Real universal suffrage doesn’t just mean the act of voting; it means a proper choice.”

Chan Kin-man, another protest leader, said the demonstrations would continue as long as the Hong Kong government fails to give a satisfactory response to their demands.

“I hope people will understand why the action keeps on escalating. It’s because the government is getting more and more closed without listening to Hong Kong people,” he said in an interview on the street. “If the government can give us a proper response in due course I think we can end the occupation immediately.”

(AP)