Niger Delta militants have clashed with Nigerian security forces after another attempt to sabotage oil infrastructure on Tuesday, local media report.

The armed group blew up a barge that was being used to repair the Trans-Forcados Pipeline, a target of recurring attacks by militants operating in the heart of southern Nigeria’s oil industry. A second dynamite attack planned for the pipeline itself was thwarted, regional leader Dickson Ogugu told the Associated Press, as the Niger Delta militants retreated following an exchange of gunfire.

The pipeline also was attacked last week, as Nigerian President Muhammadu Buhari and Niger Delta community leaders, hoping for progress in resolving their oil-related conflicts, met to negotiate in talks that some Delta militants called “humiliating.”

“We are not deterred by President Muhammadu Buhari mulling over continuous military operation,” the Niger Delta Avengers (NDA) warned in a statement on the talks posted Saturday.

Organized Niger Delta militants have opposed the oil industry for economic and environmental reasons since at least 2006, but with the renewed attacks comes the emergence of a new group, the Niger Delta Greenland Justice Mandate, which claimed responsibility for the November 2 attack.

There are tensions between the groups themselves, although they agree in a no-confidence response to Buhari’s intent.

Last week’s attack came just days after a restart of operations that were interrupted by intentional damage to the same line in July. The NDA has issued repeated warnings that attempts to repair the infrastructure it destroys will be met with additional attacks like the one in Batan.

The crippled oil operations have sent production to a nearly 30-year low and added to Nigeria’s dire economic woes, since oil accounts for 70 percent of the nation’s revenues. The conflicts compound the impact of an already-weakened oil market and cast a looming shadow on Nigeria’s ability to attract investment and advance its economic recovery.

Image: Niger Delta Avengers