Authorities have rounded up about 1,600 suspected petty criminals, including some believed to be Islamist radicals, in a nationwide crackdown aimed at halting a wave of brutal attacks on minorities and activists in Bangladesh.

Police spokesman Kamrul Islam said Saturday that officers and paramilitary soldiers had fanned out across the country Thursday night to raid suspected militant hideouts and detain about 1,600 people within 24 hours.

He said the detainees included only 37 alleged radical Islamist militants while most were suspected to be petty criminals.

Prime Minister Sheikh Hasina had announced the planned anti-militancy campaign after the wife of a police superintendent was shot and stabbed to death June 5.

Meanwhile, SITE Intelligence Group says the Islamic State group claimed responsibility for killing a Hindu monastery worker Friday morning.