New Delhi, May 9 -- Air traffic controllers in Mumbai are operating with heightened vigilance as flights through the city's airspace have surged by over 60% following escalating tensions between India and Pakistan, multiple officials said, even as scores of more flights were scrapped on Thursday. Twenty-four airports across northern India remain closed for civil aviation until at least Saturday morning, with Delhi and Dehradun now serving as the only operational northernmost airports in the country. The closures, which have led to widespread flight cancellations, came after India's targeted strikes on Pakistan and Pakistan-occupied Kashmir early on Wednesday, which was followed by attempts by Pakistani forces to strike India, which Indian o...