Turkey carried out airstrikes against Kurdish rebel targets in northern Iraq and raided pro-Kurdish political offices in Istanbul after deadly bombings blamed on the rebels hit southeastern Turkey.
State-run media said the airstrikes killed a number of militants in the Sinat-Haftanin region. Turkey often conducts similar airstrikes as part of its campaign against members of the Kurdistan Workers' Party, or PKK, which has waged a decades-long insurgency.
Police in Istanbul detained 17 suspected militants during their raids early Thursday at multiple sites in the city, including offices of the pro-Kurdish People's Democratic Party.
Wednesday's bombings included two that struck at about the same time. One was a roadside bomb in the town of Kiziltepe that killed three people, while the other was a car bomb that killed five people in a historic part of Diyarbakir. Both blasts were aimed at passing police vehicles, but ended up killing mainly civilians.
An earlier bombing, also blamed on the PKK, killed four soldiers and wounded nine others near the border with Iraq.
US offers condolences
U.S. Secretary of Defense Ash Carter offered condolences to the victims of attacks in a statement expressing Washington's solidarity with Turkey in combating terrorist activity. Both countries consider the PKK a terrorist organization.
"We stand shoulder to shoulder with our Turkish allies in strongly condemning these despicable attacks, which appear to have targeted Turkish security personnel," Carter said. "...The United States remains committed to cooperating closely with Turkey," both in the coalition of nations fighting against Islamic State extremists in the region and within the NATO alliance.
Since a cease-fire with the PKK broke down last year, more than 600 Turkish security personnel and thousands of PKK militants have been killed, according to the state-run Anadolu Agency. Human rights groups say hundreds of civilians also have died.