CANBERRA: Following the discovery of a fast-growing Covid-19 cluster in Sydney, Australians have been forced to celebrate Christmas within locked state borders due to the imposition of stricter curbs to stem the virus spread. Traditionally Christmas in Australia is spent with family and friends, and many people take the opportunity to travel elsewhere in the country to reconnect with distant relatives, reports Xinhua news agency. However, as the Sydney cluster threatened to spread, recently reopened interstate borders were slammed shut again, barring residents from Australia's largest city from entering. (IANS)