NEW DELHI, May 14 -- In a modest chamber with a high ceiling, inside one of the most secure offices in India, in a white- walled room on first floor of the imposing South Block, a phone sits atop a table. It is always manned, sometimes by a major, and at other times by a lieutenant colonel, top officials told HT on Tuesday. No one else accesses the phone. The moment he picks up the receiver, another phone rings 700 km away in the Pakistan Army headquarters in Rawalpindi and is answered by a duty officer on the other end of the line, they said, asking not to be named. And when the phone rings, it means someone in the Rawalpindi HQ has picked up their phone. This is no ordinary phone. It is the hotline between the Indian Army's director general of military operations (DGMO) and his Pakistani counterpart --- the one that was activated at 3.35pm on May 10 before the two countries announced a ceasefire that evening, ending four days of fierce fighting with Pakistan across the western border. The two DGMOs agreed to halt firing and military action on land, in the air and sea starting 5pm on Saturday, May 10. The hotline was switched on again at 5pm on Monday, May 12 for follow up action by the Indian Army DGMO Lieutenant General Rajiv Ghai and Pakistan Army's Major General Kashif Abdullah to uphold the truce. The two agreed that neither side would fire a single shot. Usually, brigadier-ranked officers from the two armies talk over the encrypted landline on Tuesdays. The two phones are manned by duty officers of the directorates of military operations of the two armies; 24 hours a day, 365 days a year. "The duty officers are the go-to men," said one of the officials cited above. "They activate the hotline and connect the two DGMOs. This communication is recorded, transcribed and analysed." The duty room in South block also holds several data rich maps of Pakistan and areas along the Line of Control (LoC), HT learns. It has a fax machine too. The cessation of hostilities on May 10 addressed fears of a full-blown shooting war. The surprise announcement capped four days of escalating hostilities that began at 1.04 am on May 7 when India hit nine terror targets inside Pakistan and Pakistan-occupied Kashmir as part of Operation Sindoor, New Delhi's retaliation for the April 22 Pahalgam attack that killed 26 people. And between the strike on the terror camps and the calling of the ceasefire, the Indian Air Force struck multiple military targets in Rafiqui, Murid, Chaklala, Rahim Yar Khan, Sukkur, Chunian, Pasrur, Sialkot, Skardu, Sargodha, Jacobabad, Bholari and Malir Cantt in Karachi. "The hotline contact is warm and cordial in the normal course. But it can be curt and business-like in extraordinary times such as now," said a second official. It has served as a constructive channel for defusing tensions along the LoC. Foreign secretary Vikram Misri announced the ceasefire around 6pm on May 10, minutes after US President Donald Trump made the surprise declaration on social media. But Misri returned at a hurriedly called and short press briefing at 11pm to confirm that Pakistan repeatedly violated the ceasefire in the evening and that the armed forces had given an adequate and appropriate response. Abdullah was warned over hotline of a "fierce and punitive" Indian response if the violations are repeated. On Monday, Ghai and Abdullah spoke over hotline for 30 minutes, with the discussions centering around upholding the May 10 understanding to stop all military actions against each other. Issues discussed included continuing the May 10 commitment that both sides "must not fire a single shot" or initiate any aggressive or inimical action against each other, and the possibility of troop reduction in the border areas. "It's hard to say how the uneasy truce will unfold on the ground as the Pakistan Army cannot be trusted. The duty officers will be working the hotline a lot more than before," said a third official. On Monday, Prime Minister Narendra Modi said that the cessation of hostilities came after Pakistan was decimated militarily and pleaded for a ceasefire. But he categorically stated that Operation Sindoor was not yet over. "We have only paused our retaliatory action against terror and military bases in Pakistan. In the coming days, every step taken by Pakistan will be monitored ...any terror attack will get a befitting response, on our terms, in our way," Modi said in his address to the nation....