A tiffin bomb exploded under a car parked on the premises of the Malappuram Collectorate (approximately 51.9-kilometres south of the city of Kozhikode) in Kerala on Tuesday, The Hindu reported. Three cars were damaged in the blast, but no casualties were reported. The car under which the bomb was placed was reportedly hired by the District Medical Officer (Homeopathy) Reji Kuzhiyellil.

Officials said they found a paper box, a pen drive and a letter reportedly written by an organisation called the Base Movement at the site of the blast. The letter – which also carried a photograph of former al-Qaeda chief Osama Bin Laden – detailed alleged human rights violations in the country, including the killing of Dadri lynching victim Mohammad Akhlaq on rumours that he had killed a calf and eaten beef. The letter also contained a map of India and the words, “Your days have been counted,” according to India Today.

Malappuram District Police Chief DK Behera said the remains of a pressure cooker were also found at the site. Behera said ammonium nitrate was used as an explosive. However, he said he had not seen the letter and would comment on it only after a forensic examination had been conducted. In June, a similar blast took place in the Kollam Collectorate, 290.2-kilometres from the Malappuram Collectorate. The Base Movement reportedly claimed responsibility for that incident as well.