PARIS: Millions of mask-wearing European children headed back to school on Tuesday after summer holidays despite rising numbers of coronavirus infections, as Hong Kong rolled out a mass coronavirus testing programme.

Schools reopened in Russia, Ukraine, Belgium and France, where teachers and their pupils aged 11 and older were obliged to wear face coverings, echoing regulations in place across the continent. Russia's 17 million school children returned to class as the country confirmed it had passed one million infections - still well behind the tally in the United States, now higher than six million.

The US is hosting the world's first major tennis tournament since the virus hit but it has not been plain sailing at the US Open, where one player was sent home after testing positive and other players are grappling with eerie empty arenas. "It's a little bit weird to play without fans and without the support and the atmosphere on the centre courts," said former champion Angelique Kerber.

The virus emerged late last year in China and has now infected more than 25 million people and killed almost 850,000. The Chinese city at the centre of the initial outbreak, Wuhan, took another leap back to normality on Tuesday when its almost 1.4 million youngsters also returned to schools and kindergartens. State media broadcast images of thousands of students hoisting the Chinese flag - a daily routine at all public schools - despite warnings to avoid mass gatherings.

European countries have faced an upsurge in cases in recent weeks after successfully suppressing the numbers, a similar story to Hong Kong where three-quarters of cases have been detected within the past two months.

However, Hong Kong's attempts to roll out a mass testing scheme have been hampered by distrust of officials following China's crushing of the city's democracy movement. Doctors and testing firms from mainland China are involved in the programme, fuelling public fears that their DNA and data will be harvested to create a system of control underpinned by biometrics.