NEW DELHI: In a major breakthrough, the NIA arrested on Friday an operative of Pakistan-based terror group Jaish-e-Mohammed (JeM) for his alleged involvement in the Pulwama terror attack last year, officials said.Officials said that 22-year-old Shakir Bashir Magrey, a furniture shop owner and resident of Hajibal, Kakapora in Pulwama, had provided shelter and other logistical assistance to suicide-bomber Adil Ahmad Dar Magrey was introduced to Dar in mid 2018 by Pakistani terrorist Mohammad Umar Farooq and he became a full-time overground worker (OGW) of the JeM.During his initial interrogation, Magrey disclosed that on several occasions he collected and delivered arms, ammunition, cash and explosive materials to JeM terrorists, including those involved in the Pulwama attack , the NIA said.Magrey further revealed that he had harboured Dar and Pakistani terrorist Mohammad Umar Farooq in his house from late 2018 till the attack in February 2019, and assisted them in the preparation of the improvised explosive device (IED).His shop is located near Lethpora bridge, and as advised by Mohammad Umar Farooq, he started conducting reconnaissance of the movement of CRPF convoy on Jammu-Srinagar Highway in January 2019, and informed Mohammad Umar and Dar about it, officials said.Magrey was also involved in modifying the Maruti Eeco car and fitting IED to it in early February, 2019, they said.During investigation, the make, model and number of the car used in the attack was quickly ascertained to be a Maruti Eeco car through forensic tests of the tiny remnants of the vehicle, which were seized from the spot during extensive searches, the NIA said, adding this has been corroborated by Magrey.The explosives used in the attack were determined through forensic probe to be ammonium nitrate, nitro-glycerin and RDX. Investigation has also confirmed the identity of the suicide bomber to be Adil Ahmad Dar through DNA matching with that of his father.The other key terrorists involved in the attack have been found to be Muddasir Ahmad Khan, JeM's Divisional Commander of South Kashmir killed in an operation by security forces on March 11, last year; Pakistani terrorists — Muhammad Umar Farooq and IED expert Kamran, both killed on March 29 last year; the owner of the car — Sajjad Ahmad Bhat, a resident of Anantnag who was killed on June 16 last year and Qari Yassir, JeM's Commander for Kashmir who was killed on January 25 this year.The attack on the CRPF convoy, moving from Jammu towards Srinagar on February 14 last year in Pulwama, with an IED-laden vehicle by Jaish terrorist Dar had claimed lives of 40 CRPF personnel and grievously injured many others.Magrey was produced before the NIA Special Court at Jammu on Friday and remanded to 15 days in NIA custody for his detailed interrogation. Further probe was underway.