MOSCOW (AP) — A building used by Russia’s Federal Security Service caught fire Thursday in the southern Russian city of Rostov, which is located about 70 kilometers (43 miles) from the border with Ukraine.

Russian state media, citing local emergency services, reported that one person died and two people were injured. The building belonged to the regional border patrol section of the Federal Security Service, or FSB, the media reports said.

Footage posted on social media appeared to show fire engulfing parts of the building, with plumes of thick smoke rising over the city. Regional Gov. Vasily Golubev said an electrical short circuit caused the fire, which in turn “caused containers of fuel and lubricants to explode.”

Citing anonymous police sources, local media had previously reported that the fire was caused by the detonation of ammunition stored in a warehouse.