An explosion rocked the mainly Kurdish city of Diyarbakir in southeastern Turkey on Tuesday, wounding several people.

The strong blast is believed to have gone off near the riot police's headquarters in the city's largely residential district of Baglar. A police source said the explosion went off in the vehicle repair section of the police compound. 

Read: What you need to know about the Turkish referendum

Reports suggested that the blast was so strong that it was heard throughout the whole city.

The Turkish Dogan news agency reported that at least four people were injured in the blast, one critically.

Turkish Interior Minister Suleyman Soylu told CNN Turk the explosion occured during repair work. 

A reporter for the Kurdish television network Kurdistan 24 tweeted a video of the smoke plumes rising over the city.

Turkey has been rocked by a series of bomb attacks perpetrated by Kurdish militant forces and extremists from the so-called "Islamic State" (IS) jihadist group. 

Last November, a car bomb in Diyarbakir killed at least eight people and injured more than 100. Turkish authorities blamed the attack on militants from the outlawed Kurdistan Workers' Party (PKK) although IS went on to claim responsibility.

The PKK has been mounting an insurgency against the Turkish government in the southeast of the country for over three decades in its pursuit for an autonomous Kurdish state.

Tuesday's attack comes just five days before Turkey holds a controversial referendum vote seeking to expand the powers of President Recep Tayyip Erdogan. The southeast has come out strongly against the Erdogan regime's quest to consolidate power. 

dm/rt (Reuters, AP, AFP)