Singapore, May 17 : Singapore and Hong Kong are for the second time postponing the start of their quarantine-free travel bubble, the Transport Ministry here said on Monday, citing "the evolving Covid-19 situation" in the city-state. The development came after a "recent increase in unlinked community cases" of coronavirus in Singapore, which last week banned dining at restaurants for one month and on Sunday announced a temporary closure of schools, reports Xinhua news agency. The latest deferral comes after the first week of flights sold out within days of the planned May 26 start date being announced. The change of plans means all travel between the two locations "will be subject to the prevailing border control and health requirements of both places", the Ministry said. A first start date late last year was shelved at the 11th hour after a similar jump in case numbers in Hong Kong. Singapore's Health Ministry on Monday announced 28 new cases of the virus, 11 of which it said were "unlinked" to previously reported cases. Singapore has reported over 61,000 cases in total, most of them diagnosed in mid-2020 among migrant workers living in crowded dormitories. The death toll is one of the world's lowest, at 31. /IANS