Hanoi, Aug 7 : Staring from Sunday, the Vietnamese capital of Hanoi will extend its current social distancing measures by another 15 days as new Covid-19 clusters have continued to emerge, authorities said. The city started applying the country's strictest social-distancing rules on July 24, but still witnessed complicated development of the pandemic in the past days with community infections, many of which with unknown transmission sources, Xinhua news agency quoted Chu Ngoc Anh, chairman of the municipal people's committee, as saying. People's negligence and the highly transmissible Delta variant of the coronavirus are posing great risks of another round of large-scale infections, according to Anh. The current social-distancing rules are in line with Directive 16 of the Vietnamese Prime Minister, according to which citizens must stay at home and not go out except for necessities and emergencies. All non-essential activities and public transport have also been halted to curb the spread of the virus, while residents should submit online health declarations daily. On Friday, Hanoi recorded 107 new local Covid-19 cases, bringing the total tally to 1,645 since the start of the latest outbreak in late April. Among the total, 1,386 were detected since early July when new clusters emerged, according to the city's Department of Health. /IANS