Saudi Arabia's attorney general sought the death penalty for five of 11 defendants charged with the murder of journalist Jamal Khashoggi as their high-profile trial opened in Riyadh on Thursday.
All 11 accused were present with their lawyers at the first session of the trial, the attorney general said in a statement carried by the official Saudi Press Agency.
Saudi Arabia had twice submitted formal requests for evidence from Turkey -- where Khashoggi was murdered inside the kingdom's Istanbul consulate on October 2 -- but had received no response, the statement added.
The names of the defendants have not been officially released. Five top officials in Saudi Arabia -- including royal court insider Saud al-Qahtani -- were sacked over the Khashoggi murder, but there is no proof they are among those charged.
Khashoggi, a contributor to the Washington Post, was murdered in what Riyadh called a "rogue" operation, tipping the kingdom into one of its worst diplomatic crises.
The 59-year-old Saudi insider-turned-critic was strangled and his body cut into pieces by a team of 15 Saudis sent to Istanbul for the killing, according to Turkish officials.
There have been reports that his remains, which have never been found, were dissolved in acid.
The defence team on Thursday requested a copy of the charge sheet and a timeframe within which to review the charges.
The prosecution agreed to both requests, SPA said. No date has been set for the next hearing.
The Khashoggi murder shocked the world at a time when Saudi Arabia and its de facto leader, Crown Prince Mohammed bin Salman, were pushing an aggressive public relations campaign to rebrand the ultraconservative kingdom as a modern state.
Among Prince Mohammed's strongest allies is US President Donald Trump, who now faces increased pressure to approve measures against Saudi Arabia.
The US has slapped sanctions on 17 Saudis in connection with the Khashoggi murder. France and Canada have also imposed sanctions on Saudis.
The US Central Intelligence Agency has reportedly concluded that Prince Mohammed very likely ordered Khashoggi's murder. A bipartisan resolution approved by the US Senate last month held the crown prince responsible for the killing.
But in November the Saudi attorney general ruled out any involvement by the young crown prince, whose reformist credentials abroad have been seriously tarnished by the murder.
The United Nations and human rights groups have called for an independent investigation into Khashoggi's killing.
"Given the possible involvement of Saudi authorities in Khashoggi's murder and the lack of independence of Saudi Arabia's criminal justice system, the impartiality of any investigation and trial would be in question," Samah Hadid, a Middle East director at Amnesty International, told AFP on Thursday.
"This is why a UN-led and independent investigation is needed into the murder."
It was unclear whether Qahtani and Ahmad al-Assiri, two senior aides to Prince Mohammed initially implicated in Khashoggi's murder, were among those on trial.
Saudi officials said in November that Qahtani -- who has not spoken publicly since then -- had been banned from travel pending the investigation but authorities have refused to disclose his whereabouts.
"It is clear that elements from high levels of the Saudi state were involved in Khashoggi's murder," H.A. Hellyer, senior associate fellow at the Royal United Services Institute, told AFP.
"There is an immense amount of international interest in this trial, but also a lot of suspicion about whether those ultimately responsible for the crime will be held to account."
Ankara, which has pledged repeatedly to allow nobody to escape justice in the case, has sought the extradition of the suspects in Saudi custody to stand trial in Turkey.
But its requests have been repeatedly rebuffed by Riyadh.
The Khashoggi affair has given rare leverage to the kingdom's rivals, not only Turkey and its ally Qatar, with which Saudi Arabia broke off all relations 18 months ago, but also arch rival Iran.
Riyadh, Saudi Arabia | AFP