Demonstrators filled the terminals, the latest in the 10th straight week of pro-democracy protests. China condemned the protests as "signs of terrorism."
Pro-democracy protests, now in their 10th straight weekend, are posing one of the biggest tests to China's leadership since the 1997 handover from Britain.
U.S. officials say the Pakistani man committed the crimes as part of a business to unlock and resell stolen phones. At least three employees accused in the case are cooperating with authorities.
Speaking in the capital, a spokesman for China's Hong Kong affairs office said protesters will be "held accountable" and said that Beijing had "tremendous power" to put down the protests.
If found guilty, the protesters reportedly could face up to 10 years in jail. Demonstrations began several weeks ago over an extradition bill and have grown to include other demands.
Protesters gathered near the site of an attack on pro-democracy activists last weekend. Police said demonstrators could face a maximum penalty of five years in prison.
Scores of protesters furious with Hong Kong's government poured into the legislative chamber and graffitied the walls. The chaos came on the 22nd anniversary of Hong Kong's return to Chinese control.
Under a "one country, two systems" policy, Hong Kong is connected to China but with its own legal protections. Protesters view the extradition bill as a threat to that arrangement.
A day after Chief Executive Carrie Lam offered her mea culpa, two top advisers followed suit. But the apologies are unlikely to be enough to placate protesters.