A Kurdish militant group claimed responsibility on Friday for a car bombing this week that killed 11 people and wounded dozens near a central tourist district in Istanbul.

The group — Kurdistan Freedom Falcons, or T.A.K. — said the attack on Tuesday had been carried out in retaliation for Turkish Army operations in the Kurdish-dominated region of southeastern Turkey, and it warned tourists to stay away from the country.

“The action was carried out to counter all the savage attacks of the Turkish Republic in Nusaybin, Sirnak and other places,” T.A.K. said in a statement, referring to areas in the southeast where the army has been fighting Kurdish militants. “We again warn foreign tourists who are in Turkey and who want to come to Turkey: Foreigners are not our target, but Turkey is no longer a reliable country for them.”

T.A.K., which claimed responsibility in February for an attack on a military convoy in Ankara, the capital, that killed 28 people, is considered an offshoot of the outlawed Kurdistan Workers’ Party, or P.K.K.