As thousands mourned a slain prosecutor, Turkey's prime minister pledged Wednesday to track down accomplices to the two assailants who had kidnapped the official, saying they were making phone calls abroad during the hostage standoff.
Two members of a banned left-wing group, DHKP-C, held a prosecutor hostage in an Istanbul courthouse for six hours Tuesday, and all three died in a shootout between the hostage-takers and police.
Prime Minister Ahmet Davutoglu suggested the hostage-takers were taking orders from abroad. He did not name the country linked to the phone calls but said the government would release more information as its investigation went on.
"I gave the orders for all sorts of operations against whoever perpetrated the incident, wherever they may be," Davutoglu said. "No one should think that the attack will go without a response."
"We shall find out where the order came from. We will investigate who is behind this network," he added.
The slain prosecutor, Mehmet Selim Kiraz, was investigating the death of a teenager hit by a police gas canister during nationwide anti-government protests in 2013.
The hostage-takers had made five demands, including demanding that the police held responsible for the teenager's killing confess the death and be tried by "peoples' courts."
Police in the southern city of Antalya meanwhile, detained 19 people suspected of belonging to DHKP-C, the state-run Anadolu Agency reported. The agency said the suspects — many of them students — were being interrogated by anti-terrorism police. Ten other suspects were detained in the cities of Izmir and Eskisehir, it said.
The DHKP-C, which seeks a socialist state, is considered a terrorist organization by Turkey, the U.S. and the European Union. The group has carried out sporadic attacks, including a suicide bombing on the U.S. Embassy in 2013 that killed a security guard. The group was more active in the 1970s.
Davutoglu, speaking in Istanbul after joining thousands of other mourners for Kiraz's funeral, said the hostage incident aimed to create chaos ahead of Turkey's June 7 general election. He criticized opposition parties for not taking part in the funeral and said the courthouse would be renamed in honor of the prosecutor.
Separately, police overpowered an armed man who stormed the ruling party's office in Istanbul, forced employees out and shouted slogans against the party Wednesday. No one was hurt in the incident.