Scores injured in blast at Kurdish opposition rally in Turkey

An explosion injured as many as 50 people at an opposition rally in Turkey's mainly Kurdish city of Diyarbakir on Friday, two days before a general election, and Prime Minister Ahmet Davutoglu said it was unclear if the blast was an accident or an attack. 

Turkish officials had earlier blamed the explosion on a faulty power transformer at the rally site but later ruled that possibility out. At least 50 people were injured, Health Minister Mehmet Muezzinoglu said, according to state-run Anatolia News Agency.

Tensions have run high as the Peoples' Democratic Party (HDP) campaigns to become the first party with Kurdish origins to win seats in parliament in Sunday's election. Previously, Kurdish MPs have joined the legislature as independents.

The HDP needs to overcome a 10 percent vote threshold, and some opinion polls show it could seize enough seats to deprive Davutoglu's AK Party of the majority it has enjoyed since sweeping to power in 2002.

"It is not yet clear whether this was an attack or an accident. Whatever caused it, we will find out," Davutoglu, referring to Friday's explosion in Diyarbakir, told supporters at a rally in the city of Gaziantep.

HDP Chairman Selahattin Demirtas called on his supporters to remain calm in a live interview with CNN Turk. "We don't know the cause of the blast," Demirtas said, adding the injuries included the loss of limbs. "It is thought-provoking that this occurred so close to the election."

Energy Minister Taner Yildiz, also speaking to CNN Turk, said it was clear the blast was not caused by an electrical fault in a power transformer at the rally site. He said the damage indicated the blast had occurred outside the generator.

Witnesses told Reuters they heard two blasts at the rally site and that the first one came from a garbage container. It was not possible to immediately verify this information. 

Television footage showed people carrying the injured on stretchers as organizers of the rally announced on loudspeakers that the explosion had been caused by a fault in a power generator and urged people to stay calm. 

The explosion rocked the parade ground just before Demirtas was to address the crowd. Police fired water cannons to disperse attendees who remained at the parade ground.

Security has been tight at HDP political rallies. On Thursday, a riot erupted in the northern town of Erzurum as nationalists clashed with HDP supporters at a Demirtas rally.

Demirtas has said his party has been the target of more than 70 violent attacks during the campaign.

President Tayyip Erdogan, who used to head the AK Party, has accused the HDP of being a front for the Kurdistan Workers' Party (PKK), which took up arms in 1984 in an insurgency that killed 40,000 people. 

Jailed PKK leader Abdullah Ocalan and Ankara launched peace talks more than two years ago.

Al Jazeera and Reuters