Image copyright POMED Image caption Jamal Khashoggi was a prominent critic of Saudi Arabia's government
Turkey has charged 20 suspects over the murder of the Saudi journalist Jamal Khashoggi in Istanbul in October 2018.
Prosecutors said an indictment accused former Saudi Deputy Intelligence Chief Ahmad Asiri and former royal aide Saud al-Qahtani with instigating the murder.
The 18 others are accused of carrying out the "deliberate and monstrous killing" inside the Saudi consulate.
Western intelligence agencies believe it was ordered by Crown Prince Mohammed bin Salman -- something he denies.
A United Nations special rapporteur says Khashoggi was "the victim of a deliberate, premeditated execution, an extrajudicial killing for which the state of Saudi Arabia is responsible".
At the time of his death the 59-year-old worked for the Washington Post and had become a prominent critic of the Saudi government.
Saudi authorities blamed a "rogue operation" for Khashoggi's death. In December, a court in the kingdom sentenced five unnamed people to death and jailed three more over the murder.
What are the charges?
According to the indictments, announced by prosecutors in Istanbul on Wednesday, Ahmad Asiri and Saud al-Qahtani were charged with "instigating the deliberate and monstrous killing, causing torment".
Image copyright Reuters Image caption A UN expert has called for an independent and impartial international inquiry
The prosecutors' statement accused 18 others of carrying out the killing - including a member of the Saudi Royal Guard, a forensics expert, and a Saudi intelligence official who has travelled with Crown Prince Mohammed in the past.
The charges were based on witness statements, an analysis of Khashoggi's digital devices, and records of the people entering and leaving Turkey, the statement said.
Saudi Arabia has not yet made a public comment about the indictments.
What happened to Jamal Khashoggi?
The journalist -- who had gone into self-imposed exile in the US in 2017 -- went to the Saudi consulate in Istanbul on 2 October 2018, seeking papers to marry his fiancée Hatice Cengiz.
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Media captionMohammed bin Salman is asked: "Did you order the murder of Jamal Khashoggi?"
Investigators believe that as she waited outside, the 59-year-old was murdered and then dismembered. Khashoggi's remains have never been found.
The gruesome killing shocked the world and UN Special Rapporteur Agnes Callamard said there was credible evidence that Crown Prince Mohammed and other high-level Saudi officials were individually liable.
She called for an independent and impartial international inquiry.