Fires that appear to have been purposely set destroyed more than 500 structures this week in and around Ethiopia’s Gijet town, an analysis of satellite imagery shared with Reuters has found, adding credibility to reports of continued conflict in parts of the northern region of Tigray.

Prime Minister Abiy Ahmed declared victory over a rebellious regional force, the Tigray People’s Liberation Front (TPLF), at the end of November after its fighters withdrew from the region’s main cities and towns. But sporadic fighting continues in some parts of Tigray, according to residents and United Nations assessments.

The government has acknowledged isolated incidents of shooting but has said that most fighting has stopped in Tigray.

Mulu Nega, head of Tigray’s government-appointed interim administration, told Reuters he had sent a team to the Gijet area to investigate.

The DX Open Network, a security research organization based in Britain, analyzed images collected by private satellite operator Planet Labs on Sunday and Tuesday around Gijet and three nearby settlements, which are about 35 km southwest of the Tigray regional capital Mekelle.

They showed at least 508 structures that appeared to have been destroyed by fire over that period, the network said, citing the blackening of earth and vegetation, ash circles indicative of roof collapse and debris from collapsed walls and ceilings.

A fire detection service run by the U.S. National Aeronautics and Space Administration (NASA), which uses visible and infrared imagery captured from space, detected numerous fires in the area on Monday, according to its website.

The DX Open Network said the absence of fire clusters or scorch marks connecting burnt structures in the images it analyzed makes it unlikely that the fires were all accidental, and there was no evidence of craters to suggest they might be the result of shelling.

“These factors support the analytic judgment that this was an intentional effort by a conflict party to destroy this civilian habitation area, and not the product of combat,” it said in its analysis. It was not clear from the images who might have set the fires.