Niger’s junta has confirmed that rebels damaged an oil pipeline carrying crude oil to neighbouring Benin.
The Patriotic Liberation Front, which is fighting for the release of former president Mohamed Bazoum, who was overthrown in a coup last July, said it was behind the attack earlier this week.
It has threatened to target oil installations and called on the Chinese companies that run the pipeline to end their support for the military regime.
It is the latest setback to hit the newly opened 2,000km (1,243-mile) pipeline as relations between Niger and Benin continue to sour.
State media said the “malicious individuals” who had sabotaged part of the pipeline would be apprehended and prosecuted.
"We know which group is the author of the act [and which also] claimed [it]," public prosecutor Ousmane Baydo is quoted by the AFP news agency as saying.
Footage aired on state-run broadcaster Tele Sahel on Friday evening showed the damage in Niger's southern Zinder region, with an oil spill stretching out into the bush.
The pipeline was formally launched at the end of last year and links Niger's Agadem oilfield to Benin’s coast - and is set to be vital to both economies.
But its future has been in jeopardy following last year’s coup, when regional sanctions were imposed on Niger.
In February, the regional bloc Ecowas agreed to lift them and borders were allowed to be reopened.
Benin’s economy had also been hit by trade block and was anxious for imports and exports to resume.
But Niger decided to keep its borders closed to goods from Benin, alleging its neighbour was hosting French forces that were training others to destabilise Niger.
The junta in Niger views France with suspicion and has established closer ties with Russia since coming to power. It kicked out French troops who had been in the West African state to fight militant Islamists threatening stability across the region.
France maintains it has no bases in Benin and such allegations are part of disinformation campaigns against the former colonial power.
Nonetheless the refusal to reopen the land border, usually busy with lorries driving back and forth, prompted Benin to block Niger’s inaugural oil exports.
China stepped into ease tensions - and Niger did manage to join the world of oil exporters, its first batch of crude leaving Benin at the end of May.
But the spat between Benin and Niger has continued.
Earlier this month five Niger nationals were arrested at an oil port in Benin on impersonation charges - and a loading of second crude shipment was reportedly aborted.
Three of the Nigeriens were given 18 months suspended sentences - and all of them, who worked for the Chinese oil firm running the pipeline, were expelled and flown to Niamey on Friday.