A Kurdish militant group has claimed responsibility for a car-bomb attack in Istanbul this week that killed 11 people and wounded 36.
In a statement posted online Friday, the Kurdistan Freedom Falcons also warned tourists that Turkey was no longer secure for them.
"We have just started the war," read the statement.
Tuesday's bomb was placed inside a car and detonated as a police vehicle went past.
The Kurdistan Freedom Falcons is considered an offshoot of the Kurdistan Workers' Party, or PKK, and has carried out several attacks in the past.
The PKK, labeled a terror organization by Turkey and its allies, is fighting for autonomy for Turkey's Kurds in the southeast.
The decades-long conflict has claimed 40,000 lives and resumed after a fragile truce collapsed last summer.