Bangladesh police said Thursday they suspect local militants may have murdered a one-legged Hindu shop owner who was hacked to death outside his store, the latest in a wave of killings of liberals and religious minorities. Police had initially said Wednesday's killing of 60-year-old Debesh Chandra Pramanik appeared to be part of a long-running dispute between him and another Hindu who was later arrested. But a top officer said the focus was now on local militants, rejecting a claim by the Daesh group that it was behind the attack in the northern Gaibandha district. Pramanik was the ninth person to be hacked to death in similar circumstances in Bangladesh since early April. District police chief Ashrfaul Islam said the fatal stabbing bore similarities to previous attacks by Jamayetul Mujahidden Bangladesh (JMB) which is also suspected of murdering another Hindu businessman in Gaibandha in February. "We suspect that members of JMB may have killed him," Islam said. Islam said Pramanik's neck had been hacked by his killers, without saying how many people were involved in the attack which took place as he opened his store at daybreak. Although no one from JMB has so far been arrested, police said an operation had been launched to detain local followers. "We've launched raids in the area," Islam said. The attack comes amid a wave of murders of liberals, secular activists and religious minorities by suspected militants in Bangladesh. Police say around 40 people have been killed by homegrown militants in the past three years, and there has been a spike in attacks in recent weeks. A homeopathic doctor was hacked to death with machetes on Friday, less than a week after a Buddhist monk was slaughtered in a similar manner. An atheist student, two gay rights activists, a liberal professor, a Hindu tailor and a Sufi Muslim leader have also been murdered since last month Although Daesh and Al-Qaeda's local affiliate have claimed responsibility for most of the murders, authorities have consistently poured cold water on their claims. Police and Pramanik's family had initially blamed a heroin addict for Wednesday's murder, saying the attack was sparked by the victim's refusal to pay extortion money. Daesh later claimed responsibility for the murder through its Amaq news agency, according to the SITE monitoring group. Bangladesh's secular government has repeatedly insisted that international Islamist groups have no presence in the country and instead blames its domestic opponents.