Tunis, Tunisia – Fifteen people were killed Tuesday when a bus carrying members of Tunisia’s presidential guard exploded in Tunis, an official told CNN.

The blast happened when the vehicle was parked near a main artery in the capital where guard members are typically picked up and dropped off, according to the official in the Prime Minister’s office.

Authorities are investigating the event as a terror attack.

Terrorist attack in Tunisia
Terrorist attack in Tunisia

Tunisia has been held up as one of the success stories of the Arab Spring, the movement that brought sweeping changes to the region. Even so, the North African nation has seen plenty of violence and turmoil, including March’s bloody attack on the Bardo Museum and a June rampage at a seaside hotel.

ISIS — the Islamist extremist group that has taken over vast swaths of Syria and Iraq while also perpetrating terror elsewhere — claimed responsibility for both of those attacks.

A state of emergency is in effect following the blast, according to local media.

As reported by CNN