Car bomb outside Turkish police station kills one officer
At least nine of the wounded were police officers, Gaziantep regional governor Ali Yerlikaya told Turkish media.
The explosion was caused by a car bomb, private NTV said. Unconfirmed reports said it was followed by sounds of gunshots.
There was no immediate indication over who carried out the attack.
Media reports showed chaotic scenes outside the imposing police headquarters in Gaziantep as ambulances rushed to help wounded lying on the ground.
Gaziantep is one of the main cities of Turkey's southeast, which has been a major hub for refugees fleeing the conflict in neighbouring Syria.
Earlier this week, an attack in the city of Bursa, northwest Turkey wounded 13 people.
Over 200 people across Turkey were killed in seven suicide bombings in the past year.