Sydney, Aug 13 (IANS): Locally transmitted Covid-19 cases in New South Wales (NSW) state, Australia's pandemic epicentre, have peaked again as it reported a record high of 390 new infections on Friday.

Of all the new locally acquired cases, the source of infection for 250 cases remains unknown, reports Xinhua news agency.

The health department was also notified of two deaths -- a woman in her 40s and a man in his 90s.

The health authorities are concerned as young people and children, who were thought to be less vulnerable in the state's previous outbreak, are being particularly affected by Delta variant.

NSW Deputy Chief Health Officer Marianne Gale said in the last 14 days, the age group of 20-29 has the biggest number of cases and the health authorities are seeing more children affected by COVID this year compared to what they saw last year.

"We are discussing those issues with the Department of Education and other industries that look after children as to what are the right measures and settings, because we are seeing more children with Covid, so that is absolutely something we monitor closely, and are consulting with experts about," she said.