Agents said the port’s 24-hour joint clearance arrangements could give cross-border tourism a major boost, although crowd control measures dampened trade at the checkpoint entrance.

Tour groups organised by Hong Kong travel agency Big Line Holiday were among the first visitors at the upgraded checkpoint on Monday morning. Chan Yin-ping, the agency’s chairwoman, said about 1,000 people had joined the tours, with 20 groups scheduled between 10am and 1pm.

Plans for further tours had yet to be decided, pending a smooth first few days of operation. The agency staggered the tours across different time slots to avoid putting too much pressure on the new checkpoint.

“But we still decided to organise the tours because today is the first day and everyone wants to make history,” she said. Chan was confident the port would give tourism a boost.

“The port is open 24 hours and Shenzhen is just across the border from the New Territories, unlike the round-the-clock crossing at the Hong Kong-Zhuhai-Macau Bridge, which involves a much longer journey,” she said.