The Union Home Ministry on Thursday decided to hand over the investigation into the Coimbatore car blast case to the National Investigation Agency (NIA). The development came on a day Tamil Nadu police made the sixth arrest in the case. K Afsar Khan (28), the sixth suspect in the case to be booked under UAPA, had been detained by the police on Wednesday. He was arrested today. An electrician by profession, Khan is a cousin of Jamesha Mubin, who had died when an LPG cylinder in his vehicle exploded early Sunday, the police said. “In addition to being an electrician, Khan participated in purchase of explosive materials through e-commerce websites,” an officer said, noting that police had seized these “explosive material” from Mubin's house after the blast. A father of two, Khan comes from Kottaimedu, close to Ukkadam, where Mubin lived. Police said Khan appears to be closely connected to Mubin's activities, as also in the alleged conspiracy plot. Khan's laptop has been seized, police said. The officer said although the “seemingly self-radicalised group” may have had a sketchy plan to strike some targets, the investigation so far shows they were neither experts nor had enough resources. "There is no indication of a specific immediate plan either, except that they were into problematic activities, were radicalised and intolerant to diverse faiths and beliefs,” the officer said. On Thursday, the state police were busy summoning, interrogating, and searching multiple locations in Ukkadam with the help of an NIA team camping in Coimbatore. Sources in NIA said the team there has visited the crime scene and met all witnesses. “They have even examined some of the arrested persons and met with the local police,” a source said. “The local police have informed that they had recovered low-intensive explosive materials, including potassium nitrate, sulphur and charcoal from Mubin’s house. They also discussed the CCTV footage retrieved from a building near Mubin’s house, which showed four men lugging a large object out of his house in Ukkadam at 11.25 pm on Saturday.” The state government said the decision to recommend handing over the probe to the NIA came considering the possibility of factors extraneous to the state and chances of international links. The five suspects who were held on Tuesday, and had been booked under provisions of the UAPA and different IPC sections, are Muhammad Thalha (25), Muhammad Azharudheen (23), Muhammad Riyas (27), Firoz Ismail (27), and Muhammad Nawaz Ismail (27). —With inputs from ENS, new Delhi