At least for an hour suspected terrorist Saifullah's brother and Uttar Pradesh Police tried to make him surrender even as he was hiding in a house in Haji Colony of Lucknow's Thakurganj area.

The invocation of Prophet Mohammad did not deter him to drop the gun. He was finally gunned down following a 12-hour siege and anti-terror operation that ended today morning.

His father Sartaj said the family will not take accept the body of an "anti-national". "He left home two months ago after I had beaten him up for not working. Last Monday he called me up and said he is going to Saudi Arabia," he said.

Sartaj said that what his son did was "not in the country's interest". "We will not accept the body of an anti-national," he said.

Top sources in the Uttar Pradesh Police told India Today that what Saifullah and his associates were planning was nothing less than "disastrous." A senior police officer said the plans if executed would have been "catastrophic".

SAIFULLAH WAS ADAMANT

All possible efforts were made by police to dissuade Saifullah but sources said he was adamant despite his family's intervention.

When Saifullah did not surrender despite persuasion by police, a meeting took place between top officers of the Uttar Pradesh Police to chalk out a strategy to discourage him from resisting security forces.

Police by then had managed to identify Saifullah's relatives and decided to rope them in to talk him into surrendering.

Senior police officers opened channels of communication and made his Kanpur-based brother Khalid speak to him for at least one hour.

Saifullah, however, was not receptive; rather he was hostile and did not respond. He was "screaming that he wanted to die".

FOCUS ON STUDIES, SAID FATHER

His brother Khalid then tried to bring in their father Sartaj to talk to him. Sartaj was in tears and tried his best to convince him but in vain. He told Saifullah that he should devote himself to studies and not terror activities.

At one point, his brother Khalid invoked Prophet Mohammad and asked Saifullah to give up in the name of Prophet. Saifullah, however, was not prepared to listen to anything. Officers said he was indoctrinated to a point where family members found it impossible to make him see the other side.

"His family members were shattered when they discovered that someone who had spent his childhood and best years of his life with them was not willing to listen to them at all," said a senior police officer.

ISIS INCREASING PRESENCE IN INDIA

When the family members failed to dissuade him, police launched a full-scale operation to eliminate him, a senior police officer said.

The Lucknow encounter shows that ISIS, which has so far asked Muslim youth to join them in the fight in Syria and Iraq, is now increasing its footprint in India with its Khorasan module .

After receiving a tip-off from police in Telangana and Madhya Pradesh, Uttar Pradesh police swooped down on Saifulla's hideout.

WHAT HAPPENED ON GROUND ZERO

Police drilled holes and used fiber-optic cameras to monitor his movement. They fired tear gas and chilly shells to force him out of the house.

ATS commandos issued a warning and stormed inside the house. Saifullah opened fire and in retaliation ATS commandos started firing.

The rooms were searched, and Saifullah was found dead. The commandos saw a wire wrapped around his stomach, possibly to carry out a fidayeen attack.

The UP police wanted to catch him alive as his interrogation could have shed light on the ISIS' Khorasan module, its plans and its sympathisers. Large cache of arms and ammunition, explosives, maps, ISIS flags were seized from the hideout.

WATCH: Lucknow encounter: Know Saifullah, the killed ISIS suspect

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