Mozambique's state radio service has announced the beheading of 10 people including children in an area where previous Islamist attacks have been reported.

The attack took place on the coast in Palma district, Cabo Delgado province, near the border with Tanzania.

'Unknown persons killed by decapitation at least 10 people in recent days in the administrative post of Olumbi, Palma district, in the north of Cabo Delgado province,' Radio Mocambique said in a brief report.

Portuguese news agency Lusa, quoting national broadcaster TVM, said two children were among those beheaded.

Palma district administrator David Machimbuko told the station that authorities had moved security teams to areas where further attacks were feared. Police spokesman Inacio Dina said officers were gathering information from a team dispatched to the north.

Local media have reported a series of attacks carried out by Islamists since October last year, when police stations were attacked in the north, a predominantly Muslim region, by Al Shabaab, an armed group with no known link to the Somali-based group of the same name.

On November 29 last year the group destroyed a church and 27 homes.

Mozambique has not been a focal point of Islamist militant activity in the past and police have been reluctant to ascribe the attacks to Islamists, though a local resident told African Independent he believed they were responsible. An eye-witness said the local village chief had been targeted because we had provided information about Al Shabaab to the police.

Muslims make up about 18 percent of Mozambique's population. Roman Catholics form the largest single religious grouping, with about 30 per cent of its 30 million people.

Additional reporting by Reuters.