People wear masks as they walk in Milan, Italy, on Feb. 24, 2020. Six people have died and 222 have tested positive for the novel coronavirus (COVID-19) nationwide in Italy, Angelo Borrelli, chief of Civil Protection Department and Extraordinary Commissioner for the Coronavirus Emergency, told a press conference at 6 p.m. local time on Monday. Photo: Xinhua

China has stepped up efforts against imported cases of COVID-19 infections amid a growing number of cases in which travelers reportedly bring the virus into China. 

The Beijing municipal government said Sunday that Beijing reported two imported cases of COVID-19 infections on Saturday. The two travelers, both Chinese nationals, who took flight from Iran and had been in close contact with the first confirmed COVID-19 patient who came back to Northwest China's Ningxia Hui Autonomous Region from Iran. The two were confirmed on Saturday and are currently under treatment. All people who had close contact with the two have been placed under medical observation. 

South China's Shenzhen also reported its first imported case of coronavirus infection on Sunday. The patient came from London and went back to Shenzhen via Hong Kong, according to media reports. A total of 93 people have been identified as having close contact with the patient. Before the case, the city had reported zero new infections for 8 consecutive days. 

Despite the obvious signs that COVID-19 outbreak is easing in China, Chinese officials and experts have been expressing concern about cases imported from abroad. 

The topic immediately trended on China's Twitter-like Sina Weibo platform where internet users shared worries that the imported cases risked reviving the spread of the virus in China.

All passengers arriving in China must file a personal health report and have their body temperature taken at customs, officials said Sunday at a press conference by the General Administration of Customs. All confirmed cases, suspected cases, people with symptoms or having close contact with COVID-19 patients would be transferred, quarantined or undergo medical observation. 

Before international flights arrive in China, National Immigration Administration officials will have already screened travelers from certain countries and regions via big data analysis, the immigration authority said on Sunday.

Passengers who enter China will also undergo a strict inspection, immigration official Liu Haitao told media. Those with travel or residence history from areas where the epidemic is severe would undergo further inspection and quarantine measures, Liu said.

A total of 7,600 confirmed coronavirus cases were found in countries and regions outside China, of which seven countries and regions reported more than 100.   

An imported contagion could lead to regional outbreaks if local governments, especially cities with large numbers of visitors, don't take strict measures, Zhou Zijun, a professor at Peking University's school of public health, told the Global Times on Sunday. 

Last week Beijing government required all returnees to the city, including foreigners, to quarantine themselves for 14 days upon arrival. A similar measure was also adopted by Shanghai. 

Some city authorities in East China's Shandong Province and Northeast China's Liaoning Province have introduced measures such as 14-day quarantines for people arriving from virus-hit Japan and South Korea, and arranging hotels for arriving foreign visitors.

But Zhou said that it was unnecessary for China to close its borders. Such a serious measure should not be taken "without a precise evaluation," he said. 

Cui Aimin, director-general of the department of consular affairs at China's Foreign Ministry said Sunday that China would pay close attention to overseas epidemics and strengthen communication and coordination with relevant countries to reduce unnecessary cross-border travel activities. 

"We hope to work with foreign parties to ensure that personnel exchanges and cooperation in various fields are not greatly affected," Cui said.