Beijing, July 27 (IANS) The virus strain behind the latest Covid-19 infection cluster in Nanjing, the capital city of China's Jiangsu province, has been identified as the highly infectious Delta variant, local authorities said on Tuesday.

The recent spike in infections in Nanjing can be attributed to the special location of the outbreak and the highly contagious nature of the strain, Xinhua news agency quoted Ding Jie, vice director of the city's centre for disease control and prevention, as saying at a press conference.

Nanjing, a mega-city with a population of more than 9.3 million, has witnessed single-day spikes of locally transmitted Covid-19 cases since a few airport workers tested positive for coronavirus last week.

It has launched a second round of all-inclusive nucleic acid testing and urged residents not to leave the city unless necessary.

--IANS ksk/