Istanbul metro explosion
Istanbul's Taksim SquareReuters

An explosion at an Istanbul metro station near central Taksim Square has caused at least one death and trains to be suspended, according to media reports.

The huge blast hit an overpass at Bayrampasa metro and was heard in many parts of Istanbul's European side. Haberturk reported that the incident was caused by a power transformer. Initial reports said that one person died and several were wounded in the explosion.

Private NTV television said the blast, which caused at least six injuries, may have been caused by a bomb

The Istanbul City Council said all metro and tram services were temporarily suspended after the blast. Istanbul Governor Vasip Sahin said the authorities have been assessing all possibilities.

Ambulances and fire trucks were seen rushing to the area.

UPDATE: Atilla Aydiner, mayor of Istanbul's Bayrampasa district claims the explosion was caused by a pipe bomb. That seems to be confirmed by reports on DHA and CNN Turk, quoting security services.