Police and security forces arrested the assailant, who is now under investigation, according to the Iranian Foreign Ministry.

Azerbaijan’s Foreign Ministry later announced a complete evacuation of the embassy staff and their families, blaming an “anti-Azberbaijani campaign” by Iran for the attack.

Tensions between Baku and Tehran have been high for years after disagreements over several diplomatic and regional issues, including Azerbaijan’s support for Israel and Iran’s backing of Armenia in the dispute over the Armenian-majority breakaway region of Nagorno-Karabakh in Azerbaijan.

Azerbaijan’s Foreign Ministry said in a statement that a “recent anti-Azerbaijani campaign against our country in Iran has encouraged such attacks against our diplomatic mission.”

A video published on Iran’s state media shows the gunman drive into a parked car outside the embassy before exiting the car with the machine gun, briefly avoiding a man standing inside a guard post.

A separate video published on Iran’s state-affiliated Fars News showed the man firing the weapon inside the embassy.