Turkish security forces shot a woman dead and detained a man Wednesday after the pair attacked Istanbul’s police headquarters.

Turkish media reported that two policemen were injured when the attackers opened fire on police stationed at the entrance of the building in Istanbul’s Fatih district.

Istanbul Police Headquarters Attacked; Woman Shot Dead

Authorities said they thought the two assailants belonged to a banned left-wing group, the Revolutionary People’s Liberation Party Front (DHKP-C).

Istanbul Police Headquarters Attacked; Woman Shot Dead

No one has claimed responsibility for Wednesday’s attack. However, Anatolia’s Voice, a website close to the DHKP-C, said in a Twitter message that the attack was a response to a police operation Tuesday to release a prosecutor, Mehmet Selim Kiraz, who had been taken hostage in a courthouse by two suspected DHKP-C members.

Istanbul Police Headquarters Attacked; Woman Shot Dead

Kiraz was shot during the standoff and died later in the hospital. The two hostage takers were killed in a shootout with police.

Following funeral services for the slain prosecutor, Prime Minister Ahmet Davutoglu vowed to hunt down those who were behind the hostage taking, saying the two gunmen were phoning people abroad during the six-hour standoff.

Turkish President Recep Tayyip Erdogan cut short an official visit to Romania on Wednesday to express his condolences to Kiraz's family.

DHKP-C recently threatened to attack police stations in Turkey, which have been targets in past attacks. The group also has been behind a series of assassinations and suicide bombings, including an attack on the U.S. Embassy.

The United States, the European Union and Turkey list DHKP-C as a terrorist organization.