A shadowy Islamist group that has terrorised northern Mozambique killed 52 villagers on April 7 after locals refused to be recruited to their ranks, according to police cited by local media Tuesday.

"Recently, the criminals tried to recruit young people to join their ranks, but there was resistance on the part of the youths. This provoked the anger of the criminals, who indiscriminately killed -- cruelly and diabolically -- 52 young people," police spokesman Orlando Mudumane told the state-owned broadcasting service.

The killings took place in the village of Xitaxi in of Muidumbe district. Mudumane said the villagers were "massacred", either shot dead or beheaded.

Police said they have launched a manhunt for the attackers to bring them to justice. Militants have in recent weeks stepped up attacks as part of a campaign to establish an Islamist caliphate in the gas-rich region, seizing government buildings, blocking roads and briefly hoisting their black-and-white jihadist flag over towns and villages across Cabo Delgado province.

For more than two years the jihadists mainly targeted isolated villages, killing more than 700 people, according to the French aid group MSF, and displacing at least 200,000, according to a local Catholic archbishop, Dom Luiz Fernando.

Thousands of people have escaped to the port city of Pemba, the capital of Cabo Delgado, seeking refuge among friends and relatives. Islamic State Central Africa Province (ISCAP), affiliated with the Islamic State group, has claimed some of the attacks in the region since last year.