Saudi Arabia will prosecute the suspects in the killing of journalist Jamal Khashoggi, Riyadh’s foreign minister said on Saturday in response to a call by Turkey for their extradition.

“On the issue of extradition, the individuals are Saudi nationals. They’re detained in Saudi Arabia, and the investigation is in Saudi Arabia, and they will be prosecuted in Saudi Arabia,” Foreign Minister Adel al-Jubeir said at a regional defence forum in the Bahraini capital.

Turkish President Recep Tayyip Erdogan on Friday called for the extradition of the 18 Saudi nationals who authorities say were involved in the murder of Khashoggi, a Saudi government critic killed in his country’s consulate in Istanbul this month.

Erdogan has called on Saudi Arabia to reveal the location of Khashoggi’s body and hand over the suspects involved in his killing.

Erdogan’s comments came after the Turkish media reported that the country’s police found no DNA traces of the Washington Post columnist in water samples taken from a well at the residence of the Saudi Arabian consul in Istanbul.

Read | Son of murdered journalist Khashoggi leaves Saudi, US ‘pleased’ over release

The leader said that the top Saudi prosecutor will travel to Turkey on Sunday to meet the top Istanbul prosecutor and argued that those responsible for killing him should face trial in Turkey, CNN reported.

After Saudi Arabia admitted that the supporter-turned-critic of Crown Prince Mohammad bin Salman was killed on October 2 in its Istanbul consulate, five high-ranking officials were dismissed, including Bin Salman’s media chief and the deputy head of the Saudi intelligence service. Eighteen people were arrested.

“Whatever happened, it comes down to these 18 persons. If you are determined, if you want to remove the suspicion and clear the air, these 18 persons are the bottom line to this,” Erdogan said, addressing the provincial heads of his ruling Justice and Development Party in Ankara.

If the Saudis can’t make the suspects talk, then Turkey will, he said. “The incident took place in Istanbul. So, hand them to us, and let us judge them.”

Erdogan described some of the statements made by the Saudis as the Khashoggi case unfolded as “very funny”.

“These juvenile statements do not match with the seriousness of government affairs… It is obvious that (Khashoggi) is killed. But where? Where is the body?”

After weeks of providing conflicting accounts of what happened to Khashoggi, the kingdom last week said that he was killed “accidentally” in a fist fight at the consulate by “rogue” agents.

But Riyadh maintained that neither the Crown Prince nor King Salman knew of the operation to target Khashoggi.

US officials have said such a mission — including 15 men sent from Riyadh — could not have been carried out without the authorization of Bin Salman, the country’s de facto ruler.

News of the Saudi Attorney General Sheikh Suood bin Abdullah Al Mo’jab’s planned trip to Turkey came a day after he said that the kingdom now considered Khashoggi’s killing to be “premeditated”, based on information from Turkish investigators.

Meanwhile, CIA chief Gina Haspel briefed US President Donald Trump on Thursday on her findings following her trip to Turkey, where she was dispatched to assess the information the Turks collected in the case.

(With inputs from agencies)