Chandigarh, April 5 -- The counter-intelligence wing of the Punjab Police, in coordination with the Chandigarh Police, on Saturday claimed to have cracked the April 1 BJP headquarters explosion case with the arrest of five accused and the recovery of a hand grenade and 10 live .30 bore cartridges. A minor explosion was reported outside the Punjab BJP headquarters in Chandigarh on April 1, with police saying a "crude" device appeared to have been hurled. No casualties were reported. The party headquarters is located in Sector 37, which also houses Law Bhavan and a petrol pump. According to officers familiar with the matter, preliminary investigations revealed that the attack was executed by a Pakistan's ISI-backed module operating under the directions of foreign-based handlers located in Portugal and Germany. "Five people involved in the incident have been arrested, and the two perpetrators involved in the attack have been identified. One grenade and another cache have been recovered so far," news agency ANI quoted Punjab DGP Gaurav Yadav as saying during a press conference. He added: "Foreign-based handlers in Portugal & Germany have been identified. Multiple cutouts and sub-modules were used. This operation has effectively foiled a major terror conspiracy... Efforts are ongoing to apprehend the main accused." A Portugal-based handler Baljot Singh, alias Jot, has been specifically identified as the coordinator for the delivery of weapons and the execution of the strike, a statement issued by police said. A senior officer said police are are searching for the two accused who hurled the grenade....