Emergency services were sent to Iskenderun in Turkey's southern Hatay province after a suicide bombing shook the town centre on Monday evening.
The blast struck Fener Street, which was closed to traffic after the incident.
The local governor blamed the explosion on one of two "terrorists" who security sources said were Kurdish militants.
"Our security forces at a control point in the town of Payas were suspicious of two terrorists and one was neutralised after they were followed to Iskenderun," Hatay Governor Rahmi Dogan said.
"And during this, there was an explosion."
No one other than the bomber was killed, but a security operation was continuing, Mr Dogan said on Twitter.
A Turkish security source said the two terrorists were from the Kurdistan Workers' Party (PKK).
The deputy police chief of İskenderun and two citizens were injured in the melee, CNN Turk reported.
The two attackers tried to escape but realising they would be caught, one detonated the bomb while the second ran away, the security source said.
Ankara has banned the PKK, which has been at war with the Turkish state since 1984.
The EU and the US have also blacklisted the Kurdish organisation.