Tunis: A Tunisian soldier opened fire on fellow troops at a military barracks in an unusual attack in the capital Monday, and the state news agency said the gunman and three others were killed.

Citing medical officials, news agency TAP said 15 people were also wounded in the attack.

It wasn’t immediately clear what motivated the soldier. Police reinforcements were sent to the area after the shooting and were combing nearby streets, and a helicopter circled overhead. The Defense Ministry said a nearby school was also evacuated.

Authorities sought to calm the public in a city where tensions remain high after an attack on the National Bardo Museum on March 18 that killed 22 people, mostly foreign tourists. The shooting at the Bouchoucha barracks was about a kilometer from the museum.

Interior Ministry spokesman Mohammad Ali Aroui said Monday’s incident is not being viewed as a terrorist attack. Speaking on national radio, he said shots were fired only inside the barracks, suggesting it was an internal dispute. Defense Ministry spokesman Belhassen Oueslati said the situation was under control by mid-morning.

Oueslati said the soldier had been forbidden from carrying a weapon, and seized another man’s weapon for the attack. He didn’t elaborate.

Since overthrowing its secular dictator in in 2011, Tunisia has been battling militant groups with links to the Islamic State group and al-Qaida, which have carri