Beijing on Friday reported two new local cases in quarantined areas, and the city has detected seven outbreaks with cases linked to areas outside the city since August, with 12 COVID-19 positive cases reported within five days, a warning to us that there should be no slackening in the implementation of solid measures to contain the epidemic, according to the authorities on Friday.

Since August 15, Beijing has reported 12 COVID-19 cases, with some found on a train arriving in the city, Liu Xiaofeng, deputy head of the Beijing municipal disease prevention and control center, said at Friday's press briefing.

The risk of infection and transmission increases due to a lengthy journey time, large passenger flow and relatively closed environment in the train, Liu said. Liu also called for those passengers who had taken the Z22, which departed from Lhasa, Southwest China's Xizang Autonomous Region on August 15 and arrived in Beijing on Wednesday, to report to the related communities voluntarily and not have contact with other people.

Both of the two cases found in Beijing on Friday had taken the Z22, and were put under quarantine as they were close contacts of confirmed cases, according to the authorities.

It's one of the effective ways to enhance screening such as nucleic acid testing within 24 hours, and the city also needs to strengthen prevention and control management for those residents coming to or returning to Beijing such as self-health monitoring at home, a Beijing-based immunologist told the Global Times on Friday.

As the autumn semester approaches, teachers, students and other employees of primary and secondary schools, kindergartens and nursery schools can return to campuses seven days after they arrive in Beijing, said the authorities.

Civil aviation and railway departments should strengthen remote inspection and screening, and those who enter Beijing should present a negative nucleic acid test taken within 48 hours and a healthy green code. They also need to conduct a nucleic acid test within 72 hours after they arrive in Beijing, said the authorities.

All the personnel returning to or coming to Beijing should present a negative nucleic acid test before returning to work and strengthen health monitoring, according to the authorities.

This round of flare-ups involved more than 20 provincial-level regions across the country, with some regions such as South China's Hainan Province seeing a rapid growth in infections. Experts noted that rapid preventive measures including nucleic acid tests should be conducted in a timely way along with long-term research into vaccines and medicines treating COVID-19.