Analysts of the country said the incursions, in gas-rich Cabo Delgado province, show how a once shadowy insurgent group is seeking to broaden its appeal among local residents, while launching bigger and bolder attacks that are overwhelming demoralised soldiers and triggering a humanitarian crisis in Mozambique's poorest corner.

Since March, the few international aid groups working in Cabo Delgado have mostly pulled back to the province's capital city, Pemba, leaving behind a growing number of internally displaced people with little support.

Though many analysts say the handing out of looted goods indicates a strategic attempt to win "hearts and minds", residents and witnesses of recent attacks said the group has no mercy for those who step out of line.

Changing strategy

When the militants launched their first attack in Cabo Delgado more than two and half years ago, residents recognised them as members of a local Islamist sect that had emerged in the province a few years earlier.

Nowhere to run

But the so-called "hearts and minds" campaign has not stopped tens of thousands from fleeing their homes in recent months, nor gruesome attacks on dissenters - including 52 people reportedly killed in April after refusing to be recruited by the insurgents.