Srinagar, Nov. 12 -- Hours after the car blast near Red Fort in New Delhi left 13 people dead, J&K Police carried out overnight raids and picked up four people, including brother of the Pulwama-based doctor, Umar Un Nabi, who was in contact with the two other doctors from Kashmir arrested after the Faridabad terror module was busted and 2,900kg of explosives were recovered. His father was also detained for questioning and mother was taken for DNA sampling. "We have taken the mother of the suspect to collect DNA samples in order to match with the parts found at the scene of the blast," an official said. Two brothers of the suspect accompanied their mother to the hospital. His father, Ghulam Nabi Bhat, was picked up by the police from his residence at Koil in Pulwama, hours after his wife was taken for a DNA test, the officials said. Police said Dr Umar is a vital link to the blast at Red Fort as the Hyundai i20 car was bought by him. While Dr Umar Un Nabi has been missing since investigation into the Faridabad terror module began, three of his relatives were picked up for questioning from Koil village in Pulwama district of south Kashmir. "A person linked to the Faridabad module is suspected to have been travelling in the i20 car though the identity of the deceased will only be confirmed after the DNA test," a senior police official said. Three of the six people arrested were identified as Amir Rashid Mir, a plumber, Umer Rashid Mir, a power development department employee, and Tariq Malik, a J&K Bank security guard. "They are being interrogated by a special police team," he said. "Many people have been picked up earlier in connection with the ongoing investigation of the terror module that was busted in Faridabad on Monday," the official said, adding the operation that led to the unearthing of the white-collar terror network started on October 19 after the recovery of Jaish-e-Mohammad posters in Nowgam on the outskirts of Srinagar. The police investigation blew the lid off the terror module in which two doctors were among seven people arrested following the recovery of 2,900kg of explosive and inflammable material, assault rifles, pistols and improvised explosive device-making components in Faridabad on Monday. The arrests were part of the broader transnational crackdown on the Jaish-e-Mohammad and Ansar Ghazwat ul Hind's urban support cells. The seven people arrested on Monday are Arif Nisar Dar, alias Sahil, Yasir-ul-Ashraf and Maqsood Ahmad Dar, alias Shahid, all three from Nowgam, Maulvi Irfan Ahmad of Shopian, Zameer Ahmad Ahanger, alias Mutlasha, of Ganderbal, Dr Muzammil Ahmad Ganaie, alias Musaib, of Koil, Pulwama, and Dr Aadil Rather of Wanpora, Kulgam. A police spokesman said the accused were part of a radicalised ecosystem that identified potential recruits, raised funds under the guise of professional or social initiatives and arranged logistics for terror activities. During investigation, the name of Dr Umar had come up as he belonged to the native village of Dr Muzamil. However, he has been missing since the arrest of the two doctors. For the past five days, J&K Police have carried out raids on dozens of houses across Jammu and Kashmir as, the sources said, there were fears of a terror attack. "The raids were being carried out as a preventive measure," the spokesman said....