Joburg/Maputo — When a group of suspected Islamist militants beheaded 10 villagers in Mozambique’s gas-rich north late last month, it ratcheted up concerns that spreading attacks in the remote region could threaten a potential $30bn in investment.

Anadarko Petroleum and Eni, which are developing separate offshore gas projects near the Tanzanian border, say they have not been affected by the violence in Cabo Delgado province.

London-listed explorer Wentworth Resources says it has not been able to gain access to its onshore licences near the town of Mocimboa da Praia, due to safety concerns as a result of the attacks.

"This problem is not going to go away and is increasingly becoming a regional problem," says Nigel Morgan, director of Rhula Intelligent Solutions in the capital, Maputo.

"This is a risk issue for oil and gas investors in Cabo Delgado."

The assaults began in October, when a group of men armed with guns, knives and machetes targeted police stations in Mocimboa da Praia, leaving five police and 12 assailants dead.

In response, the authorities detained 133 people, including 32 from Tanzania.

‘Extremist elements’

Since then, there have been 20 attacks by "extremist elements" in the area in the first four months of this year, according to the Terrorism Research & Analysis Consortium.

Those figures do not include the May 27 beheadings in which two of the victims were children.

In more recent violence, attackers used machetes to kill seven people and set fire to 164 homes late on Monday in a village in the district of Macomia between Mocimboa da Praia and Palma, police spokesman Inacio Dina told reporters on Tuesday in Maputo.

A day before, police said they had killed nine suspected insurgents in the region.

What first emerged as a religious group in the far north of one of the world’s poorest nations, had by the end of 2015 incorporated military cells, according to a study by Muslim cleric Saide Habibe, and Maputo-based academic researchers João Pereira and Salvador Forquilha.

It was initially known as Ahlu Sunnah Wa-Jama, which is Arabic for "adherents of the prophetic tradition", but local residents call it al-Shabaab, the same name used by militants in Somalia.

Isolated region

Already the group has grown to consist of more than 100 cells, though it is difficult to know how many members it has in total, says Pereira, a political science professor at Eduardo Mondlane University.

Geography contributes to the problem. Mocimboa da Praia, where the attacks started, is 1,800km northeast of Maputo, and Palma, where the offshore gas reserves that Eni, ExxonMobil and Anadarko are developing, is about 80km north of that.

The group attracts mainly jobless youths in Cabo Delgado, where poverty runs deep in the rural areas, according to the research by Pereira, Habibe and Forquilha.

To stand out, they wear white turbans, shaved heads with large beards, robes and black shorts. The leadership has links with religious, commercial and military circles of Islamist militant groups in Tanzania, Somalia, Kenya and the Great Lakes region of East Africa, they said.

Rubies and ivory

Funding for their operations comes from trading in rubies, ivory and timber — all of which Cabo Delgado has in abundance. The area has also become a key landing site for heroin shipments that are then trafficked onward to Europe and neighbouring SA, according to research by the Global Initiative Against Transnational Organised Crime.

The group is probably learning from other militants in Africa and may mimic techniques used by Boko Haram in Nigeria and al-Shabaab in Somalia, said Habibe.

Mozambican authorities have responded to the attacks by arresting hundreds of people and closing some mosques. A heavy-handed response from the government could worsen the situation, Pereira says.

"If the repression is too large, the group may use other more sophisticated techniques such as bomb attacks," he says. "Elimination of the group depends on regional military action, combined with social investment and intelligence action."

Much could also depend on how countries to the north like Kenya are able to combat the penetration of the radical groups into Tanzania and how that country can eliminate the routes to Mozambique, Pereira says.

"It is clear that state institutions like the police, intelligence and military do not have this situation under control," says Morgan of Rhula.