Mumbai has reported a surge in COVID-19 cases after reaching a record low in recent days. On Wednesday, the city registered about 25 per cent growth in new cases within a day. The rise is seen in a few areas out of the 24 civic wards. Parel, Mulund and Dahisar are showing more than double the average cases in the last week. Though it cannot be termed as a trend, it can help the BMC trace and track patients and their contacts.