RESIDENTS of Naunde village were woken by gunshots at around 2am on June 5th. Two of the attackers carried guns. The other three, armed with machetes, set houses on fire. Then they chased down a local chief and hacked off his head in front of horrified neighbours. They also killed six others, including an Islamic leader whom they beheaded in a mosque.

The attack, documented by Human Rights Watch, a pressure group, is one of several dozen carried out by jihadists in Cabo Delgado—a mostly Muslim, coastal province in Mozambique’s far north—since October 2017. Recently many have followed a similar pattern: hit-and-run raids during which attackers torch houses, steal supplies and behead victims. In May terrorists decapitated ten people, including children. Officials have tried to brush off the violence as mere banditry. But the attacks appear to be increasing.

Who the killers are and what they want is not entirely clear. Uncertainty surrounds even their name. They are known as Ahl al-Sunnah wal-Jamaah (Arabic for “followers of the prophetic tradition”), though locals also refer to them as al-Shabab (“the youth”). They have no known ties to the jihadist group in Somalia, which is also called al-Shabab, but some researchers think the jihadists in Mozambique have received training abroad.

Beyond touting a strict form of Islam, the group’s political agenda is rudimentary. According to Joseph Hanlon of the London School of Economics, Ahl al-Sunnah wal-Jamaah emerged when groups of street traders, united by economic frustration and radical Islam, came together in 2015. They urged people not to pay taxes or send their children to state schools—and they stormed into mosques, knives waving, to lambast local Islamic practices.

For years locals complained about the growing number of angry young men in their midst. But Mozambique’s corrupt and listless authorities did little. The group’s first attack, last October, took officials in the capital, Maputo, by surprise.