The explosions occurred at the pro-Kurdish People's Democratic Party, or HDP, final election rally as party leader Selahattin Demirtas was preparing to address the crowd in Diyarbakir, the main city in Turkey's predominantly Kurdish southeast.
Rally organizers urged calm, saying a malfunctioning power distribution unit caused the explosions, but witnesses said there were two separate blasts spaced by five minutes. Energy Minister Taner Yildiz said that the blasts were not the result of a malfunction but were caused by an "external interference" with the power unit, though he did not say whether he believed they were caused by a bomb.
The explosions come at a tense time, two days before Sunday's parliamentary elections in Turkey, in which the Kurdish votes will be critical.
The party is vying to pass the threshold of 10 percent of total votes required to take seats in parliament. If it succeeds, it could make it impossible for the ruling AKP to reach a supermajority in parliament. That would scuttle the AKP's ambitions to introduce a new constitution and change Turkey's parliamentary system into a presidential system that could give President Recep Tayyip Erdogan executive powers. Prime Minister Ahmet Davutoglu said authorities would investigate the cause of the explosions.