Emergency services said they put out the flames within 30 minutes and rescued five people from the second floor of the building.

Regional police said in an online statement that it apprehended a man in his late 30s suspected of the attack on Kosmos after he sought medical assistance.

A source close to the investigation told the Znak.com news outlet that Denis Murashov, 39, claimed during an interrogation that he carried out the attack to prevent the screening of Alexei Uchitel’s “Mathilde.” The film, due for release in late October, depicts Tsar Nicholas’ love affair with ballet dancer Mathilde Kschessinska.

The attack on the Kosmos center took place two days after it hosted the Ural Open Festival of Russian Cinema. More than 20 screenings had been scheduled for Monday, Sept. 4., according to the festival’s website.

Kosmos announced on its website that all film screenings would be postponed until Sept. 7, while concerts would go ahead as scheduled.

Yekaterinburg Mayor Yevgeny Roizman labeled the incident an act of “terrorism.”