Victoria has recorded four new local COVID-19 cases as authorities scramble to find the source of the state’s Delta strain cluster, previously known as the Indian strain of the novel coronavirus. The Department of Health reported the cases along with six overseas acquired infections on Sunday, as Melbourne endures its second weekend of lockdown. The ten total cases, from almost 30,000 tests, take the number of active infections in the state to 87. It is not yet clear whether the new infections are linked as Victorian contact tracers continue to try and to track down the source of another two “mystery” cases. Two cases were a couple, who have been infectious in the community. They were among five new local cases reported in the state on Saturday. One of the pair had been a regular visitor to Craigieburn Central shopping centre and came forward for testing as a result of health …