Australian officials are closing the border between Australia’s two most populous states from Tuesday for an indefinite period as they scramble to contain an outbreak of the coronavirus in the city of Melbourne. The decision announced on Monday marks the first time the border between Victoria and New South Wales has been shut in 100 years. The number of COVID-19 cases in Melbourne, Victoria’s capital, has surged in recent days, prompting authorities to enforce strict social-distancing orders in 30 suburbs and put nine public housing towers into complete lockdown.