Tuesday's blast was caused by a "percussion bomb planted by the separatist terrorist organization", Guler said, using the official jargon for the Kurdistan Workers' Party (PKK).

He added that a man arrested earlier this week in Istanbul with 3.5 kilogrammes (7.7 pounds) of plastic explosives was also a PKK member.

The PKK, which has been fighting since 1984 for self-rule in the country's mainly Kurdish southeast, last week threatened retaliation following Turkish air strikes on their bases in northern Iraq.

The group, which has been blacklisted as a terrorist group by Ankara and much of the international community, has in the past carried out bomb attacks in urban centres.

Tuesday's blast occured in the suburb of Kucukcekmece, on Istanbul's European side. Thirty-year old Fatma Agdemir died Wednesday from her injuries, a hospital spokeswoman told AFP.