MOSCOW (AFP) — A man opened fire and wounded a recruitment officer at an enlistment center in Siberia on Monday, the local governor said, as tensions mount over Russia's military mobilization for the conflict in Ukraine.

The incident occurred in the town of Ust-Ilimsk in Irkutsk, a vast and thinly populated region of southeastern Siberia.

"In Ust-Ilimsk, a young man fired at the military registration and enlistment office," Irkutsk governor Igor Kobzev said in a message on Telegram.

Kobzev said a military commissar had been wounded in the shooting and was in critical condition.

The shooter was immediately arrested, he said, and "will definitely be punished!"

"I am ashamed that this is happening at a time when, on the contrary, we should be united. We must not fight with each but against real threats," Kobzev said.

"I have given instructions to strengthen security measures. I ask everyone to remain calm," he said.

Russian President Vladimir Putin announced a partial mobilization of reservists on Wednesday as Moscow's forces face setbacks in the seven-month conflict in Ukraine.

The announcement sparked panic and demonstrations, with hundreds detained across the country.

Critics have accused authorities of focusing mobilization efforts in remote parts of the country like Siberia and the North Caucasus, to avoid sparking opposition in major urban centers and especially Moscow.

Call-up boo-boo

Meanwhile, Russian authorities on Sunday promised to fix the mistakes in their troop call-up for Ukraine, after some public outrage over students, older or sick people being mistakenly ordered to report for duty.

When Putin announced a partial mobilization on Wednesday, he said only people with "relevant" skills or military experience would be concerned.

But many expressed outrage after seeing — sometimes absurd — cases of authorities summoning people unfit for service.

Authorities in the southwestern Russian region of Volgograd sent a 63-year-old diabetic ex-military staffer to training camp, despite poor health and cerebral issues.

The 63-year-old came back home Friday night, according to Russian state agency RIA Novosti.

In the same region, 58-year-old school director Alexander Faltin received a call-up order despite having no military experience.

His daughter posted a video on social media that became viral.

He was allowed home after his documents were reviewed, according to RIA.

Several students told AFP they were given call-up papers, despite Russian authorities promising they would be left out of the recruitment drive.

On Saturday, Putin signed a decree confirming students in secondary vocational and higher education institutions would be exempted from mobilization.

Detained anti-mobilization protesters said police gave them call-up papers in custody — ordering them to enlist in the very effort they were denouncing.

But the Kremlin defended the procedure on Thursday, saying "it isn't against the law."