Tour buses arrive one after another in To Kwa Wan, Hong Kong’s blue-collar community, unloading groups of mainland Chinese tourists outside large restaurants who come here for a simple meal.

Tourists wearing white, red and orange baseball caps, the color of which indicated which tour group they belonged to, crowded the sidewalks, some smoking under “No Smoking” signs and rushing through the glass door of a real estate office, where real estate agent Nikki Lin was annoyed.

“They are very noisy,” said Ms. Lin, who complained that some tourists used the bathroom and water dispenser in her office without asking permission.

“I’ve had tourists come in and ask me if I have any good food recommendations,” she added. “I look at him and say, ‘This is real estate.’ ”

China closed its borders after the coronavirus pandemic broke out in early 2020. Only in recent months have cheap tour groups from the mainland returned to Hong Kong, reigniting tensions in a city that has been transformed by Beijing’s political crackdown.

Mainlanders and their wealth had been pouring into Hong Kong before the pandemic, sending property prices and rents soaring and fueling resentment among residents that has sometimes morphed into outright discrimination. Criticism of the mainland has been muted since Beijing imposed a sweeping national security law on Hong Kong nearly three years ago to assert its political dominance.

Now, the Hong Kong public’s reaction to low-budget tourists, who join tours for as little as $175 for two days, has been less than enthusiastic and sometimes downright rude.

Local residents also said that these tour groups of 20 to 30 people were too noisy, obstructing traffic, and some people squatted outside to eat boxed lunches, which was unsightly. In Repulse Bay, where multi-million dollar mansions are hidden, a tour group ate cup noodles loudly outside a public toilet, which embarrassed the locals.

Even some members of Hong Kong’s Legislative Council, which is composed entirely of pro-Beijing figures, have lost patience.

“Can we have some quality tour groups?” Yeung asked colleagues at a recent legislative session, holding up photos of tourists pouring into parts of Hong Kong.

Mainland tourists were the main force of Hong Kong’s tourism industry before the epidemic, accounting for nearly 80% of inbound tourists in 2018. After the outbreak, Hong Kong adopted some of the world’s strictest prevention and control measures, and local restaurants, hotels and shops lost business. The low-cost tours came as the government tried to revive tourism in this city of 7.5 million people. But high-spending tourists have not appeared in large part due to the lack of flights.

Budget travelers from the mainland are not subject to flight restrictions because they arrive by bus or ship, but local business owners complain about the spending habits of these tourists, who often buy only a few items at local drugstores, like a visitor to New York who buys only a tube of Neosporin from Walgreens.

“Most of the low-price groups are elderly people who don’t spend much money,” William Zhang, a drugstore operator in Kowloon, said recently after a hectic six minutes that tour guides allot for shopping at each store.

Tourists cleared out the ointments and instant coffee in the pharmacy, but no one cared about big-ticket items such as ginseng.

On anti-government forums online, the tour groups are providing fodder for ridicule, recalling the time when local residents publicly used the word “locusts” to insult mainland Chinese shoppers in Hong Kong, many of whom bought in bulk baby formula, medicines and cosmetics sold at lower prices on the mainland and brought them back to the mainland for resale.

The ridicule goes both ways. Mainland users of Douyin, the Chinese version of TikTok, have been making hidden-camera videos mocking the poor Mandarin of Hong Kongers, who mainly speak Cantonese. Others have posted videos of themselves being snubbed by waiters in restaurants because they believed they spoke Mandarin.

On the second deck of a white and pink car ferry turned floating restaurant in Victoria Harbor recently, tour guide Miyou Wang watched dozens of mainland tourists devour a few ordinary dishes, including egg drop soup, stir-fried lettuce and a dish of mostly potatoes with roasted chicken and potatoes.

She has been working in the tourism industry for 20 years and says Hong Kong people are pretentious.

“I have to take care of dozens of tourists at a time,” Ms. Wang said of complaints about rude behavior. “I can’t possibly manage everyone.”

Hong Kong Tourism Board Director Kevin Yeung called on the public to be more accommodating and called for stricter supervision of tourists.

“Tourists crowd the streets, but that’s a sign of economic development,” Mr. Yeung said in a recent television interview. “Hong Kong people used to be hospitable, and it’s time to bring that spirit out.”

To cope with the growing crowds, the government sent police to places like To Kwa Wan to direct bus traffic and set up crowd-control barriers on sidewalks to steer tourists toward restaurants.

“I actually wanted to come here during the three years of the epidemic, but I didn’t make it,” said Zhang Zhanbin, 43, a tourist from Hebei Province, China. This was his first time in Hong Kong and the four-day trip cost about $400.

Mr. Zhang, a worker in a rubber factory with a big curly moustache, doesn’t care about the complaints at all because Hong Kong has returned to Chinese hands and is no longer a British colony.

“I’m not too worried about Hong Kong people discriminating against us,” he said. “After all, Hong Kong has been returned to China.”

Hong Kong was supposed to maintain a high degree of autonomy for 50 years after its return to Chinese rule in 1997. The protests that engulfed Hong Kong in 2019 were meant to preserve those freedoms, but ultimately failed. Signs of Hong Kong’s authoritarian turn are now visible throughout the city, from billboards promoting National Security Education Day to banners praising speeches by Xi Jinping, China’s top leader.

The changes have made Hong Kong more attractive to mainland tourists, such as Guo Xiuli, 56, a retired civil servant from the southern city of Chaozhou, who took photos on a recent morning at Golden Bauhinia Square, a popular tourist attraction near the downtown financial district.

Ms. Guo, who is not on a budget tour group, said she was treated with more respect this time than during her first visit to Hong Kong in 2004, when she felt she was the target of prejudice because of her Mandarin.

“I used to feel rejected, especially when I was talking or asking for directions, they ignored me and were impatient,” said Ms. Guo, who was photographed wearing red velvet high heels and a mask made of lace and rhinestones.

“I think it’s because the mainland economy has developed,” she continued. “That’s why Hong Kong doesn’t seem so special anymore.”