At least 30 people were injured when an unknown person threw a grenade in a nightclub in central Burundi, a senior police official said Sunday. Five people were seriously injured by the grenade itself when it exploded early Sunday, said Gitega police chief Col. Stany Nkurunziza, according to AP. The other more than 25 people were injured in the stampede that followed the attack as patrons of Gitega's only nightclub tried to flee. Police are investigating the motive for the attack and looking for the attacker, who fled during the stampede, Nkurunziza said.