NEW DELHI: A sergeant in the IAF who visited the Nizamuddin area in Delhi during the Tablighi Jamaat congregation there last month has been quarantined at the Palam airbase along with two other personnel whom he had closely interacted with thereafter.IAF sources on Saturday said “contact tracing” and other investigations were underway, though the sergeant has denied attending the Tablighi congregation during his visit to Nizamuddin, which has emerged as a super-spreader of Covid-19 in the country. “The sergeant and the two other IAF personnel are asymptomatic as of now but have been quarantined,” said a source.An Army doctor in Kolkata, a junior commissioned officer (JCO) in Dehradun and a jawan from the Ladakh Scouts in Leh had earlier tested positive for Covid-19 in the armed forces.As earlier reported by TOI, both the doctor, who is a Colonel posted at the Eastern Army Command hospital in Kolkata, and the JCO had travelled to Delhi in the second week of March before the lockdown came into place.The first confirmed coronavirus case in the Army was a 34-year-old soldier from the Ladakh Scouts at Leh, whose father had returned from a pilgrimage from Iran on an Air India flight on February 27. The case had led to a virtual lockdown of the Ladakh Scouts Regimental Centre there.