A suicide bomber detonated an explosive device outside Turkey's interior ministry in the capital, Ankara, on Sunday the Turkish government said.
Two officers were wounded in the blast that killed the bomber. Authorities "neutralized", or killed, the other attacker, the Minister of Interior Affairs, Ali Yerlikaya said.
The attack took place hours before parliament was set to reopen.
In his speech to lawmakers later on Sunday President Recep Tayyip Erdogan, condemned the attack, saying: "The villains who threaten the peace and security of citizens have not achieved their objectives and will never achieve them."
A news site close to the Kurdistan Workers' Party (PKK), which Ankara has long considered to be a terrorist organization, said it has claimed responsibility for the attack.
How the attack unfolded
According to minister Yerlikaya, the two attackers drove up to the interior ministry in a car, one jumped out at the entrance gate and charged the building.
"One of the terrorists blew himself up and the other terrorist was neutralized," Yerlikaya said. He added that two police officers were "slightly injured" in the fire caused by the blast.
Ankara police said it that it was carrying out "controlled explosions" of "suspicious packages" to prevent other explosions.
The attackers targeted district is home to several other ministries and the Turkish parliament.
Ankara's chief public prosecutor launched an investigation into the attack, Turkish media reported. Officials also limited access to the scene and imposed a news blackout on the attack.
Sweden's NATO bid to be considered by Turkish parliament
This fall session of Turkey's parliament must consider Sweden's bid to join NATO.
Erdogan dropped his opposition to Sweden's NATO bid earlier this year after earlier accusing it of being soft on exiled Kurds affiliated with the PKK.
He did not elaborate in the bid during his speech during Sunday's opening of parliament.
But Erdogan slammed his country's long wait for accession to the EU and said Turkey "no longer expects anything from the European Union, which has kept us waiting at its door for 40 years."
"We have kept all the promises we have made to the EU, but they have kept almost none of theirs," he said, adding that he would not "tolerate any new demands or conditions" for his country to join the bloc.
rmt/dj,lo (AFP, AP, Reuters, dpa)