United Nations human rights chief Michelle Bachelet on Wednesday said that an international investigation was required to determine those responsible for the murder of Saudi journalist Jamal Khashoggi in October, Reuters reported.

“I do believe it is really needed in terms of ensuring what really happened and who are the [people] responsible for that awful killing,” Bachelet said when asked about the need for an international inquiry.

Meanwhile, Turkey’s chief prosecutor has demanded that arrest warrants be issued against two Saudis close to Crown Prince Mohammed bin Salman over the murder, AFP reported. The chief prosecutor’s office filed an application Tuesday to obtain the warrants for Ahmad al-Assiri and Saud al-Qahtani, described in court documents as being “among the planners” of the Khashoggi’s murder.

Al-Assiri and al-Qahtani were sacked after Riyadh admitted Khashoggi was killed in the Saudi consulate in Istanbul on October 2. According to Turkey, a 15-member Saudi team was sent to Istanbul to kill Khashoggi. Turkish President Recep Tayyip Erdogan has said the order to kill the journalist came from the highest levels of the Saudi government, but insisted it was not Salman.

In the United States, Central Intelligence Agency Director Gina Haspel gave a closed Senate briefing to members of Senate committees on Tuesday. Senators said they are more certain after the briefing that the crown prince had a role in the murder, BBC reported.

Republican Senator Lindsey Graham said he had “high confidence” Salman was complicit in Khashoggi’s murder. Graham described Salman as a “a wrecking ball”, “crazy” and “dangerous”.

“There is not a smoking gun - there is a smoking saw,” Graham said in a reference to Khashoggi being allegedly dismembered in the Saudi consulate.

Democrat Senator Bob Menendez said the US must “send a clear and unequivocal message that such actions are not acceptable in the world’s stage”.

Khashoggi, a vocal critic of the Saudi regime, went missing on October 2 when he was last seen entering the Saudi consulate in Istanbul for paperwork for his marriage. Initially, Saudi Arabia claimed to have no knowledge about his disappearance but later admitted that agents working without Riyadh’s knowledge had killed him.

On November 15, Saudi Arabia said it had indicted 11 suspects for the murder and prosecutors had sought the death penalty for five of them.

A day later, the Central Intelligence Agency of the US found that Salman had ordered Khashoggi’s killing. But US President Donald Trump has continued to supported Salman, saying that the CIA report has not conclusively blamed the crown prince for the murder.