A total of 15 suspects were detained as part of nationwide police operation after a deadly blast in Turkey's northwest, Interior Minister Efkan Ala said, according to Anadolu Agency.

The detentions came a day after a suicide attack at the entrance of a historic bazaar in Bursa in northwestern Turkey that killed one person.

"There are strong signs of an organization. [...] There are findings. When the organization is finalized, I will explain, 15 people are in detention. I cannot say which provinces at the moment," Ala told reporters in Ankara ahead of a meeting.

Earlier, local police sources said 12 suspects were detained in operation in Bursa, Istanbul, western Afyonkarahisar and southeastern Sanliurfa provinces.

The suicide blast injured 20 people at the entrance of a historic bazaar in Bursa, Turkey’s fourth-largest city, on Wednesday afternoon.

The Bursa Governor's Office said a female suicide bomber was involved in the attack.

/By Azertac/