The Kerala Police has said that a pen drive found at the site of a tiffin bomb explosion at Malappuram Collectorate contains photos of political leaders including Prime Minister Narendra Modi, The Indian Express reported on Thursday. While three cars were damaged, no casualties were reported from the explosion on Tuesday.

Thrissur range Inspector General MRA Kumar said investigators had found some similarity between the Malappuram blast and another explosion at the Kollam Collectorate in June. Kumar said there were indications that the Base Movement, which reportedly claimed responsibility for the Malappuram incident, would conduct more strikes. “The pen drive recovered from the blast site has given details about previous operations,” Kumar added.

Meanwhile, another investigating officer said that a National Investigation Agency team had visited the site of the explosion and held discussions with police officials. This came as a report in The New Indian Express suggested that the intelligence arm of the Tamil Nadu police had alerted their Kerala counterparts to the possibility of such incidents a week ahead of the Malappuram blast. A senior intelligence officer told the daily that the alert was sent to both the Kerala Police as well as central intelligence agencies.

On Tuesday, a letter reportedly written by the Base Movement was found at the site of the explosion along with the pen drive. 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.”