Delhi on Wednesday reported 2,509 new Covid-19 cases, making it the highest single-day spike in nearly 2 months. With 19 deaths, the Covid-19 toll in the capital stands at 4,481. While there are 16,502 active cases, Delhi has now registered 1,79,569 confirmed Covid-19 cases. The spike has been attributed to the opening up of the borders, return of migrant workers and increase in the number of coronavirus testing.