Hong Kong is gearing up for a massive influx of visitors during the upcoming five-day May Day holiday, with about 4.61 million people expected to enter or leave the city during the Chinese mainland's first long break since the resumption of cross-boundary travel.

The Immigration Department estimated that among the inbound and outbound travelers, 84.9 percent, or 3.91 million, will pass through land ports.

This year, the five-day break on the mainland, a popular season for tourism, falls from Saturday to Wednesday.

The busiest day for outbound travelers will be Saturday, with 359,000 people expected to leave the city while the largest crowd of incoming visitors — 422,000 people — may come on Monday, according to the department. Among all the 13 ports, the department estimated that the Lo Wu checkpoint will welcome the most, with about 1.13 million people passing through.

Various departments of the special administrative region's government have prepared for the influx, according to a government statement on Wednesday.

The Tourism Commission on Monday held a cross-departmental meeting to coordinate arrangements for welcoming visitors to Hong Kong.

To assist passengers in making travel plans, visitors can check the estimated waiting status at land border control stations on the Immigration Department's mobile app.

"It is expected that cross-boundary passenger traffic from April 29 to May 3 will be much heavier than usual. To avoid congestion during the morning and evening peak hours at each land boundary control point, we appeal to mainland visitors and local residents to cross the boundary during nonpeak hours," a government spokesperson said.

The Immigration Department will upload daily figures on its website (www.immd.gov.hk) from Sunday through Friday, May 5. Information on the latest passenger flows at major attractions will be linked to the Hong Kong Tourism Board website (www.discoverhongkong.com) for reference.

Hong Kong has seen a rise in visitor numbers from the mainland since the full reopening of border ports in February. On April 5, the Tomb Sweeping Day holiday, about 56,000 tourists from the mainland entered the city.

The number of visitors from the mainland is expected to increase during the May Day holiday, as it is the first long break on the mainland since Hong Kong and the mainland resumed full cross-boundary travel. It was reported earlier that about 70 percent of the city's hotel rooms were booked by mid-April.

The Interdepartmental Joint Command Centre set up by Customs, the Police Force, the Immigration Department and other relevant departments will be activated during the May Day holiday to monitor the situation at each land control point, as well as to maintain close liaison with mainland counterparts and take contingency actions where necessary.

During the May Day holiday, government departments will strengthen personnel and coordinate transportation and customs clearance services at various control points, including crowd management, parking for tourist buses and transport frequency.

The Travel Industry Authority has advised travel agents receiving mainland inbound tour groups to stagger arrival times to avoid overcrowding. The authority and Customs will deploy additional personnel during the break to conduct inspections and step up enforcement in districts where many registered shops for tour groups are located to avoid unfair trade practices such as coerced shopping.

The Tourism Commission is updating tourism authorities in Guangdong and Shenzhen about the situation for mainland tourists coming to Hong Kong to ensure that tourists enjoy a high quality of service, the statement said.