Local cases of COVID-19 on the Chinese mainland have been declining over the past 10 days, said Mi Feng, an official from the National Health Commission (NHC).

The news came as China approaches its national holidays (April 30 to May 4) for International Workers' Day on May 1.

Before the pandemic, May 1 holidays were one of the busiest periods for the country's transportation system as people traveled.

For this year's holidays, the free highway policy will remain in place, which exempts the highway fees for passenger vehicles that have seven or less seats.

With that said, officials recommended people to not visit places marked as medium or high risk for COVID-19. They also cautioned about the difference in COVID-19 control measures in different areas of the country.

While some medical staff can enjoy the holidays, the NHC requires all hospitals to make sure the emergency services remain open 24/7 during the period.

China has registered over 550,000 local infections since early April. The situation remains to be complex and needs strict control measures in place, said Mi.

Nearly 1.25 billion people in China have been fully vaccinated, of which 215 million are elderly.

Cases drop for the sixth day in Shanghai

Shanghai recorded its lowest daily number of new COVID-19 cases in more than three weeks as the municipal government pledged to ease restrictive measures while supporting manufacturing businesses to ramp up resumption of production.

The city government announced on Wednesday that residents living in areas that have zero COVID-19 community transmission are permitted limited mobility.

The Chinese financial hub, home to 25 million people, is conducting another round of nucleic acid and antigen testing based on each residential compound's current risk level, and the list of closed-off, controlled and precautionary areas will be adjusted based on test results, according to a local health official.

'Health code' in Beijing under foreign network attacks

More places in China's capital city Beijing were marked as medium or high risk on Thursday as local health personnel work hard on the second round of nucleic acid tests.

Chaoyang District sampled 3,841,506 people on Wednesday and found seven sample tubes positive. The district is conducting epidemiological survey on the positive samples and will conduct the third round of testing on Friday.

All high, middle and primary schools in Beijing will enter the May 1 holidays one day in advance, which means no school time for Friday. The time shift also applies to all kindergartens in the city.

With that said, the entrance exams and processes for those schools and the college entrance exam (gaokao) are unlikely to be postponed.

What's more, local officials revealed that hacking attempts from foreign countries were detected on Thursday on "Beijing Health Kit," an online service that provides health code and vaccination status. The risk has been mitigated by the service's maintenance team, according to the officials.