(Adds comments from Vice Premier Sun Chunlan)
* Beijing COVID outbreak enters 10th day
* Shanghai reports 2nd day of zero cases outside quarantine areas
* Shanghai starts to loosen curbs for some areas
By Ryan Woo and Brenda Goh
BEIJING/SHANGHAI, May 1 (Reuters) - The Chinese capital Beijing tightened COVID restrictions on Sunday as it battled an outbreak, while Shanghai let more of its 25 million residents venture out for light and air after reporting a second day of zero infections outside of quarantine areas.
The outbreak in Shanghai, which began in March, has been China's worst since the early months of the pandemic in 2020. Hundreds of thousands have been infected and the city has forbidden residents from leaving their homes, to great public anger.
Vice Premier Sun Chunlan, personally in Shanghai to oversee the city's counter-epidemic work, said on Sunday that while now is not the time to relax, communities with no new cases for seven days should be allowed to return to "normal social order".
The outbreak in China's most populous city and the risk of a spread in Beijing are testing the government's zero-COVID approach that has placed tremendous pressure on local economies in a year when Xi Jinping is expected to secure an unprecedented third term as president.
Beijing, with dozens of daily infections in an outbreak now in its 10th day, has not locked down. More than 300 locally transmitted cases have been logged since April 22.
But on Sunday the capital tightened social distancing rules and launched a new round of mass testing in its worst-hit district.
The city of 22 million has in the past week conducted mass testing in most of its 16 districts, suspended all entertainment venues and banned restaurant dining.
"The impact of all this on us is too great - 20,000 yuan ($3,000) in a day gone, just like that!" said Jia, a manager at a burger restaurant in the east of Beijing.
"Our boss is stressing out about this too," Jia said, asking to be identified only by his surname. "We have three branches in Shanghai. They've all been shut and losing cash for a month. And now this."
Beijing's Universal Studios theme park closed on Sunday, while in the highly visited Badaling section of the Great Wall, visitors were told to show proof of negative COVID test results before entering.
Chaoyang district, accounting for the biggest share of infections in Beijing's outbreak, started an additional round of mass testing, with public health workers knocking on doors to remind residents to get tested.