Hong Kong (CNN) Several high-profile pro-democracy leaders were swept up in a series of arrests on Thursday and Friday in Hong Kong, ahead of what will be the 13th consecutive weekend of mass protests in the Asian financial hub.

Activist Joshua Wong, who led the city's massive pro-democracy protests in 2014, and former Legislative Council candidate Agnes Chow were arrested on Friday and Andy Chan, the leader of a banned pro-independence party, was detained by police on Thursday. In total, seven were arrested in connection with past protest-related offenses, police said.

The arrests could further inflame tensions in the city after an already tense week. Last Sunday, a Hong Kong police officer fired a live shot into the air during protests for the first time. Later in the week, Chief Executive Carrie Lam refused to rule out invoking emergency powers and a prominent protest organizer was attacked by masked men carrying baseball bats and knives.

Wong and Chow were released on bail Friday evening. Addressing journalists on the steps of the courthouse, Wong said told reporters that "the Beijing government are the ones who back and endorse Hong Kong police to conduct such a mass arrest and prosecution."

Chow described the arrests as a scare tactic, telling reporters, "We can see very clearly that the regime and the HK government is trying to create a White Terror to try to scare Hong Kong people to not participate in the social and democratic movement of the future."

A mass rally had been planned for Saturday, but was canceled on Friday amid news of the arrests and after the organizers failed to secure authorization from the police. "Our first principle is always to protect all the participants and make sure that no one bears legal consequences because of participating in the protest that we organized," said Bonnie Leung, vice convener of organizing group Civil Human Rights Front (CHRF).

Activists could face 5 years in prison

In addition to the arrests of Wong and Chow, outspoken pro-democracy politician Rick Hui was arrested on Friday. Hui was arrested Friday on suspicion of "obstructing the police officers in the performance of their duty." The charge relates to Hui's alleged participation in a rally in Sha Tin, in Hong Kong's New Territories.

Andy Chan, founder of the outlawed Hong Kong National Party, had been arrested at Hong Kong International Airport the day before. Police said he was charged with "suspicion of rioting" and "assaulting a police officer."

Chan was among eight arrested in early August for possession of offensive weapons and suspected bomb-making materials.

Police charged Wong, 22, with "inciting others to participate in unlawful assembly", "organizing unauthorized assembly" and " knowingly participating in an unauthorized assembly."

Chow, also 22 and a former Demosisto Legislative Council candidate, was charged with "inciting others to participate in unlawful assembly" and "knowingly participating in unauthorized assembly."

The pair could face five years in jail if convicted of the most serious charge of "inciting others to participate in unlawful assembly."

Three more arrestees were not named, but police described them as two women suspected of breaking into Hong Kong's Legislative Council, and a 59-year-old man suspected of rioting.

Demosisto tweeted Friday that Wong was "forcefully pushed into a private minivan on the street in broad daylight" near a subway station in a southern district on Hong Kong Island at around 7:30 am, local time.

BREAKING: Our secretary-general @joshuawongcf was just arrested this morning at roughly 7:30, when he was walking to the South Horizons MTR station. He was forcefully pushed into a private minivan on the street in broad daylight. Our lawyers following the case now. — Demosistō 香港眾志 (@demosisto) August 30, 2019

Demosisto said on Friday that the arrests were meant to "spread fear" and that there is now "no room for dialogue" with the government.

On Friday, there was confusion within the group over whether an arrest warrant had been issued for former party chair Ivan Lam. The group later tweeted that he had not been arrested. CNN has not confirmed Lam's whereabouts and has reached out to police for comment.

The director of Amnesty International Hong Kong described the arrests as an "outrageous assault on the rights to freedom of expression and peaceful assembly."

Pro-democracy Demosisto party member Agnes Chow speaks to passing pedestrians in Hong Kong on June 4, 2017.

"This past week, we have seen scare tactics straight out of Beijing's playbook: pro-democracy protest organizers attacked by thugs, prominent activists arrested after being snatched from their homes and streets, and a major rally planned for Saturday banned," said Man-kei Tam.

Chinese troop movement ahead of planned rallies

The three arrests come as China said it was rotating fresh military troops to the Hong Kong garrison.

Chinese Defense Ministry spokesman Ren Guoqiang said the China's People's Liberation Army troop "rotation" in Hong Kong was a "routine arrangement" and the timing was "similar to previous rotations."

Hong Kong protester's 5 demands Fully withdraw the extradition bill Set up an independent inquiry to probe police brutality Withdraw the characterization of protests as "riots" Release those arrested at protests Implement universal suffrage in Hong Kong

China has stationed troops in Hong Kong since it was turned over to the Chinese in 1997 from Great Britain.

The People's Liberation Army troop movements were carried out in the dead of the night and took place at the same time as a rotation of the garrison in neighboring Macao. They were announced by Chinese state media early Thursday morning.

But the movement sparked skepticism among United States defense officials.

"This is the time to start worrying," one unnamed US official told CNN. The specific concern in the next few days is that the Chinese troop movements, including tactical vehicles and personnel carriers, puts Beijing's forces into a more immediate position to crack down on pro-democracy rallies.

"We are monitoring the Chinese military movements in and around Hong Kong closely," Pentagon Lt. Col. David Eastburn said in a statement. "We stand with the G7 countries in calling for violence to be avoided and in reaffirming the importance of the Sino-British Joint Declaration."

Wong has been jailed before

Wong was the face of the 2014 Umbrella Movement and has been a visible fixture of the recent protests, giving media appearances and offering commentary on his Twitter feed.

He was released from prison in June, a day after protest organizers said 2 million Hong Kongers took to the streets to march against the extradition bill with China. He walked free after serving one month of a two month sentence related to the 2014 protests.

In August 2017 , Wong, and two other leaders of the 2014 Umbrella Movement protests, Nathan Law and Alex Chow, were sentenced to between six and eight months in prison for public order offenses stemming from the protests, which shut down parts of the city for several months.