I'm Stuart Mackintosh with the BBC News. Hello. The World Health Organization has acknowledged there's emerging evidence that the coronavirus can be spread by tiny particles suspended in the air. The senior official said airborne transmission couldn't be ruled out in crowded, closed, or poorly vented settings. On Monday, an open letter from over 200 scientists accused the WHO of underestimating the possibility of airborne transmission. One of the signatories to that letter, Joe Allen from Harvard University, told the BBC that ensuring air quality must be a priority. We still have to put in all the control strategies that we know we're working, including hand washing, mask wearing and physical distancing. The additional control strategy that has to be put in place that we've been encouraging organizations to do for a long time is to bring in more fresh outdoor air, and any air that recirculated in the building has to run through higher efficiency filters. If you're in your home, open up your windows, bringing more outdoor air.
The United States has officially begun the process of withdrawing from the World Health Organization. Washington says it will leave the organization in July next year. But Mr. Trump's Democratic Party rival Joe Biden, said he would rejoin the WHO on his first day as president if he won the US election in November.
Donald Trump has urged schools to reopen on schedule for the next term in August and September, saying it was important for the country. Despite a rise in the rate of new coronavirus cases in many states, Mr. Trump said he would put pressure on governors to ensure that schools opened. He said some had closed for political reasons. Mr. Trump strongly criticized the decision by Harvard University to switch to online courses for the next academic year. I think it's ridiculous. I think it's an easy way out and I think they ought to be ashamed of themselves. And probably others are doing that. That's called easy way out. I don't know if people are helping them. I guess their endowment is plenty big. They don't have any problem with that. Thousands of protesters have clashed with riot police in the Serbian capital Belgrade after the government announced a weekend curfew in the city in response to a rise in coronavirus infections. At one point, crowd stormed the parliament building. This report from Grant Ferrett.
Demonstrators surged through crowd control barriers and into the parliament in Belgrade. Hours earlier, President Aleksandar Vucic announced the weekend curfew, as well as a ban on all public gatherings of more than five people. The protesters were forced out by police, equipped with batons and shields, but many remained on the streets late into the night. They demanded the resignation of the president, accusing him of mishandling the crisis. World news from the BBC.