Two people have died following two explosions at a Kurdish party election rally in south east Turkey.
Mehdi Eker, the country's agriculture minister, said more than 100 people were injured in the explosions.
Health Minister Mehmet Muezzinoglu had earlier said around 50 people were hurt in the incident and 20 to 24 of them were being treated in hospitals.
The blasts occurred five minutes apart at the pro-Kurdish People Democratic Party's election rally in Diyarbakir, in Turkey's predominantly Kurdish south east.
Rally organisers first said a malfunctioning power distribution unit caused the explosions, but the country's energy minister said they were caused by an "external interference" with the power unit, without saying whether he believed a bomb was involved.
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% of total votes required to take seats in parliament. If it succeeds, it could make it impossible for the ruling AKP to reach a super-majority 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.
"Whatever is behind this incident - whether it was a power transformer explosion, an assassination attempt, an act of provocation - we shall investigate it," he said. "I call on my brothers in Diyarbakir - please beware of exploitation of the incident and provocations. No one should be involved in provocations."
The rally was cancelled but a large group of youths remained at the site, protesting against the explosions. Some threw stones at a police water cannon that moved in to disperse the crowd.
Mr Demirtas urged calm. "Whatever the cause, I invite the people to retain their common sense," Mr Demirtas said. "Whatever happens, Turkey is in need of peace."