Sounds of explosion were heard outside the office of the Punjab BJP office in Sector 37 here on Wednesday evening.The sounds were heard around 5 pm, said state BJP leader Vineet Joshi.Senior police officers, including Senior Superintendent of Police Kanwardeep Kaur, reached the spot to take stock of the situation. Police cordoned the area.Joshi said police is investigating the matter.Chandigarh SSP Kanwardeep Kaur said it was too early to determine the exact nature of the blast-like sound. “It seems a two-wheeler was impacted,” she said. Further details are awaited.