An explosion has hit a political rally in Turkey, triggering panic and leaving several people injured just days before parliamentary elections.

The cause of the blast, which happened in the south-eastern city of Diyarbakır, was not immediately clear. Local press reports suggested it could have been a fault with a power distribution unit.

The explosion came just 30 minutes before politician Selahattin Demirtas was due to address a rally of his pro-Kurdish Peoples' Democratic Party (HDP).

Images from the scene posted on social media showed thick black smoke engulfing the streets where the political parade was being held, with people being rushed away on stretchers.

Organisers of the rally told the crowd a faulty power generator had caused the explosion and urged calm, according to reports from Reuters.

At least 10 people are being treated at a local hospital, the Anadolu news agency said.

Diyarbakır is a majority Kurdish city where the HDP is hoping to secure crucial votes on 7 June to reach the 10% threshold required to enter parliament.