The UN has called for urgent measures to protect civilians in Mozambique's Cabo Delgado province, where Islamist militants have stepped up attacks and there have been reports of beheadings and kidnappings.

The UN High Commissioner for Human Rights, Michelle Bachelet, warned that the population was in a desperate situation - trapped in conflict-affected areas with barely any means of survival.

She called on the Mozambican government to guarantee unhindered access for humanitarian agencies.

More than 350,000 people have been displaced by the violence over the last three years, the UN says.

Since mid-October, more than 14,000 people have fled by sea to the provincial capital, Pemba.

Dozens have died when their boat capsized.