A police inspector and a villager were killed after protests over alleged cow slaughter swirled out of control in Uttar Pradesh’s Bulandshahr district and a mob attacked security personnel who opened fire during the melee, officials said on Monday.

Protesters, including members of right-wing groups, clashed with securitymen and set their vehicles and a police post on fire in the three-hour rampage after reports of cow slaughter at Mahaw village on Sunday night, said Prashant Kumar, the additional director general of police (Meerut zone).

Inspector Subodh Kumar Singh died of injuries, probably caused by a blunt object, he said. A 21-year-old man, identified as Sumit, died of gunshots, Kumar said, adding that only the post-mortem would reveal if the bullets were fired by police.

Singh was involved in the investigation in the murder of Mohammad Akhlaq, a resident of Uttar Pradesh’s Dadri village who was lynched by a mob in September 2015 over another incident of alleged cow slaughter.