Fighters linked to Islamic State took control of a northern Mozambican port town that’s been a key logistics link for a $23 billion natural-gas project being built by Total SE, according to Risk Advisory Group. It’s the third time this year the insurgents have seized Mocimboa da Praia, located about 60 kilometers (37 miles) south of the LNG project and the closest harbor. About three months ago, fighters that first pledged allegiance to IS in 2018 occupied it for as long as three days.

The site of Total’s project is in the preparation stage, with the company having recently finalized an initial $15 billion of financing and the town is among several access points to bring in supplies, including a port and airport at the development. The fighting, though, shows an escalation of insurgent attacks in the region that authorities are battling to contain. “The capture of Mocimboa da Praia, as well as the previous assaults on district capitals since March, shows that the capabilities of IS militants has improved,” Tristan Gueret, an analyst at RAG in London, said by email on Wednesday.

Total didn’t immediately respond to emails seeking comment. Gas projects in the country’s northern-most Cabo Delgado province are central to plans to transform the impoverished southeast African nation. Projected revenue from the developments are estimated at more than three times its current gross domestic product.