The Kurdish Freedom Falcons (TAK) posted a statement on its website, said it had carried out the bombing in Istanbul on Tuesday in revenge for Turkish operations in the Kurdish-dominated southeast.

"The action was carried out to counter all the savage attacks of the Turkish Republic in Nusaybin and Sirnak and other places," said the group, an offshoot of the Kurdish Workers Party (PKK).

In the statement, posted in four languages including English and German, the TAK warned foreign tourists from visiting Turkey.

"We are again warning all foreign tourists who are in Turkey or wish to come to Turkey," said the group. "Foreigners are not our target, but Turkey is no longer a safe country for them."

The group, which labeled Turkey "colonial" and "fascist," said the ruling Justice and Development Party (AKP) "obstinately insists on a wild war against the Kurdish people is responsible for the civilian deaths."

Seven of the fatalities in Tuesday's Istanbul attack were said to be members of the security forces, while four civilians were also killed.

Tourist area targeted

The bomb struck near Istanbul's Vezneciler metro station, which is within walking distance of tourist hotspots, including the Grand Bazaar and the Blue Mosque. The front of a converted Ottoman mansion, the popular Celal Aga Konagi Hotel, was damaged in the blast.

The latest attack represents another blow to Turkey's image as a tourist destination. So far this year, tourist visitor numbers have fallen by almost 30 percent.

The attack on Tuesday was followed by an attack in Mardin province in the southeast of Turkey, which killed six people including a pregnant policewoman. That bombing was claimed by the PKK.

Turkish Prime Minister Binali Yildirim said on Wednesday that the PKK had made a renewed bid for peace, but vowed there would be no negotiation. "There's nothing to discuss," said Yildirim.

The Turkish military said on Friday that its jets targeted and killed between eight and 10 suspected PKK militants near the Iraqi border late on Thursday.

Although little is known about the TAK, it is considered to be more radical than the PKK, which focuses its attacks on the southeastern conflict zone. The group is believed to have split away several years ago.

rc/sms (Reuters, AFP, AP, dpa)