Airports in India went on high alert Thursday following fresh attack warnings, and officials said the country suspects two senior leaders of a banned Pakistani militant group orchestrated last week's deadly Mumbai attacks. Early Friday, security forces swarmed the international airport in New Delhi after the sound of gunfire rang out, but no one was injured, police said. Police spokesman Rajan Bhagat said a handful of shots were apparently fired but no one was seen shooting. He said: "It was not a terrorist incident. No one was killed. ... There was no attack on the airport." Initial reports from the British Broadcasting Corp. said six gunmen had been shot and killed by security forces at the airport. A later BBC report said police denied anyone was injured.