OUAGADOUGOU, Burkina Faso (AP) — At least 15 soldiers were killed in northern Burkina Faso when their vehicles hit land mines, including a rescue team that hit a second explosive device when they were rushing to help, the army said.

The explosions took place in the Bam area of the Center-North region, the army said in a statement issued late Tuesday. The first vehicle hit a roadside bomb near the town of Namsiguia, it said. When the rescue team responded a second device exploded.

“The results of the two incidents show 15 fallen soldiers and one injured. Material damage was also recorded,” said the army statement. “The Chief of the General Staff of the Armed Forces sends his condolences to the families of the victims and his wishes for a speedy recovery to the injured. To the units, he sends his warm encouragement for all the efforts made.”

No group has yet taken responsibility for the attack and investigations are underway, the army said.

Burkina Faso is grappling with soaring jihadi violence linked to al-Qaida and the Islamic State group that’s killed thousands and displaced nearly 2 million people.