A mock drill is underway at various Delhi hospitals to check COVID-19 preparedness amid a surge in cases of the viral disease in the national capital. Delhi reported 699 Covid cases and four deaths due to the infection on Sunday, and 484 cases with a positivity rate of 26.58 per cent and three fatalities on Monday. Delhi Health Minister Saurabh Bharadwaj on Monday said a report on the March 26 mock drill was submitted to the chief minister and other authorities.