A large explosion hit Turkey's mainly Kurdish city of Diyarbakir on Tuesday, injuring at least four people, ABC News reported.

Ambulances and police were sent to the scene of the explosion in the city's Baglar district, where thick smoke was seen rising into the air, the private DHA news agency reported.

The cause of the explosion was not immediately known. The private NTV news channel said, however, that the explosion occurred while repair work was being carried out on an armored police vehicle. It said the blast caused part of a building to collapse.

One of the injured was in serious condition, the station said.

Turkey is on edge following a string of deadly bomb attacks carried out by Kurdish rebels or Islamic State militants in the past two years.

Source: MENA