The feud between the mercenaries of the Kremlin-connected Wagner Group and the ordinary Russian army appears to be escalating, amid reports of exchanges of friendly fire.

Russian soldiers shot at Wagner paramilitaries near Bakhmut — the eastern Ukrainian town which has seen brutal attritional battles for territory — destroying a truck, the mercenary group claimed Sunday evening.

In response, Wagner claimed to have detained the commander of the Russian army’s 72nd brigade, on Monday releasing a video of him appearing to confess to giving the order to fire on the mercenaries’ vehicle, claiming he did so while drunk because he personally disliked the group. The officer, who introduced himself as Lieutenant-Colonel Roman Gennadievich Venivitin, appeared to have been roughed up by his captors.

The video came after Wagner released a statement, signed by a “commander” of the group, stating that he had received information that members of the official Russian army had been seen “mining the roads in the rear zone” of Wagner’s positions around Opytnoye and Ozarianovka, two towns in the Bakhmut area, on May 17.

Wagner forces began clearing the mines from the roads, but had to stop after coming under “small arms fire” from a Russian army brigade in Semigorje, a town about 20 kilometers south of Bakhmut, the statement said.

No one was injured in the attack, which destroyed a service truck, according to the Wagner statement. POLITICO has not been able to independently verify this information.

The incidents appear to be an escalation in Wagner chief Yevgeny Prigozhin’s ongoing dispute with Russian military leaders, including Defense Minister Sergei Shoigu and Chief of the General Staff of the Russian Armed Forces Valery Gerasimov.

Russian oligarch-turned-warlord Prigozhin has repeatedly accused the Kremlin’s high command of withholding ammunition from Wagner forces fighting in Bakhmut, which has seen some of the fiercest fighting of the war.

Two weeks ago, Prigozhin said his troops had started handing over their positions in Bakhmut to the Russian military, five days after claiming that Wagner controlled the city — which Kyiv has disputed.