In a sign of the times, officials in Hong Kong are gluing down bricks ahead of a visit by a top Chinese official, a move reportedly aimed at stopping protesters from turning pieces of pavement into projectiles.

The road work is part of a sweeping security mobilization that includes counterterrorism measures, such as road closures and barricades near the city’s central business district. Demonstrators will be relegated to protest zones, drawing complaints that the government is trying to play down dissent.

The man at the center of the storm: Zhang Dejiang, a member of China’s highest political body and the top official responsible for Macau and Hong Kong. Zhang lands in Hong Kong on Tuesday for a three-day trip. He will be the highest-ranking cadre to visit the city since pro-democracy protests in 2014.

Judging by the security preparations, not everyone is looking forward to his visit.

Anger and frustration over Beijing’s influence in Hong Kong affairs has been on the rise since 2014, when protesters occupied the heart of the city for months calling for free and fair elections.

More than a year and a half later, the issues raised by the demonstrators remain unresolved and many worry that Beijing is tightening its grip on the former British colony, threatening rule of law and the free press.

Amid crackdown on a Hong Kong publishing house this winter, Lee Bo, a local bookseller with a British passport, disappeared from a warehouse in the city and surfaced across the border in mainland China under truly unbelievable circumstances.

In a series of strange — and most probably forced — communiques, Lee said he secretly smuggled himself across the border to “assist with an investigation.” He later delivered a bizarre — and, again, apparently forced — account on Chinese TV.

Dissatisfaction with Beijing’s role in the special administrative region has given rise to “localist” groups that are pushing for greater autonomy and are willing to fight, literally, to protect Hong Kong’s language and culture.

In February, a Lunar New Year crackdown on street vendors selling a local favorite, fish balls, led to clashes with police. Protesters tossed bricks and garbage cans; police brandished weapons — a show of force that is exceptionally rare in safe and prosperous Hong Kong.

Zhang is not in town to discuss Hong Kong’s future; the official purpose of his visit is to deliver a speech at a conference on one of President Xi Jinping’s pet projects, the proposed orgy of infrastructure spending known as “One Belt, One Road,” or the "New Silk Road."

Zhang, who has previously warned Hong Kong not to "politicize everything" and focus instead on economic integration with the mainland, is unlikely to go off script.  Still, the city’s pro-democracy camp no doubt hopes to broaden the agenda if it can, using his presence as a chance to raise concerns.

At least four representatives from pro-democracy parties will have the opportunity to meet with Zhang at a cocktail reception on Wednesday, according to a report in the South China Morning Post.

Lawmaker Emily Lau told the paper that she would attend the event and use the occasion to raise the bookseller case.

Another invitee, legislator Cyd Ho, said she would not attend. "We hope to have a proper work meeting with Zhang Dejiang on the pressing issues facing Hong Kong,” she told the paper.

“We don’t want to just exchange pleasantries at a cocktail party.”

Correction: An earlier version of this post misspelled the name of Chinese President Xi Jinping.