(CNN)An explosion rocked an intersection near a subway station Tuesday evening in Turkey's most populous city, Turkey's semiofficial Anadolu Agency reported.
Explosion injures 5 near Istanbul subway, official says
Five people were injured in the blast in Istanbul's Bayrampasa district, said Atilla Aydiner, the district mayor.
There was conflicting information about the cause of the explosion. Aydiner, speaking to Turkish television, said a bomb caused it. State broadcaster TRT also said the blast was caused by a bomb.
However, Istanbul's city government, in a statement on its website, said the explosion's cause was unknown and under investigation.
Details on what led Aydiner to believe that a bomb was involved weren't immediately available.
The explosion happened around 6 p.m., Anadolu reported.
Video footage from the scene showed a riot police bus passing by moments before the explosion. Police are looking for a suspect who was seen at the site before the blast, and investigators are looking into whether the attack might have been targeting the bus.