French group Total suspends work at gas plant near Palma despite authorities’ claims order has been restored.

The attack bore all the hallmarks of the Islamist insurgents that have terrorised Mozambique’s far northern Cabo Delgado region for the past three years. Gunmen converged on a refugee-filled town. They waited, cutting off access by road. Then, at about 4pm on March 24, they opened fire.

More than a hundred insurgents laid waste to the coastal town of Palma, destroying civic buildings, robbing and setting fire to at least one bank and killing dozens of people, according to Mozambican officials, security consultants and a report by the African Union seen by the Financial Times. Thousands fled the violence.

On Sunday Mozambique’s army said that the town was safe again and “significant numbers” of insurgents were dead after days of battle.

But analysts said the attack on Palma was an inflection point in what has until now been a widely ignored African war. The town is about 15km from a multibillion-dollar natural gas investment and, after hundreds of staff had to be evacuated to safety, its future is under threat.

Even as President Filipe Nyusi insisted that the Palma attack “was not greater than others [in the past]”, French energy group Total suspended the $20bn development, which lies on the nearby Afungi peninsula and is Africa’s biggest private investment.