As international pressure mounts on Riyadh over the fate of missing Saudi journalist Jamal Khashoggi, a Qatari human rights group urges Saudi authorities to immediately reveal the whereabouts of four Qatari citizens, who were forcibly disappeared in the kingdom last year.

In a statement issued on Sunday, the Doha-based National Human Rights Committee (NHRC) expressed “grave concerns” over the fate of the four victims and held the Saudi government responsible for their safety.

NHCR head Ali bin Samikh al-Marri called on the United Nations’ Working Group on Enforced or Involuntary Disappearances to send a mission to Saudi Arabia to investigate the cases.

Marri censured the Saudi actions as “shameful and inhumane,” urging the international community to exert pressure on Riyadh to respect international law and release the detainees.

“What the Saudi authorities are doing towards Qatari nationals is shameful and inhumane,” he said, adding, “It will leave a major psychological mark on future generations.”

The NHRC has also called on the UN High Commissioner for Human Rights to intervene and secure the release of the Qataris.

“The NHRC has provided international organizations and the UN with all information about the missing and detained Qatari citizens in Saudi Arabia,” Marri said.

The four Qatari citizens have been arrested in Saudi Arabia since the outbreak of a diplomatic rift in the Persian Gulf region, which pits a Saudi-led quartet of states against Doha.

Saudi Arabia, the United Arab Emirates (UAE), Bahrain and Egypt cut their diplomatic ties with Qatar on June 5 last year and imposed a sea, land and air blockade on the country, accusing it of sponsoring terrorism and destabilizing the region. Qatar strongly denied the allegation.

The NHRC’s statement comes as Riyadh has come under scrutiny over the disappearance of dissident Saudi journalist Khashoggi, giving rise to a sense of urgency among the Qataris to find out about the fate of their nationals.

Turkey says it has evidence the dissident journalist had been murdered inside the consulate by Saudi operatives.

Qatari journalist Majed al-Khelaifi said he was “worried” over the fate of the missing Qataris in light of Khashoggi’s case, saying the journalist’s disappearance was a “dark reminder” of what could have happened to the Qatari nationals, al-Jazeera reported.

The disappearance of the Saudi journalist nearly two weeks ago inside the Saudi consulate in Turkey’s Istanbul has caused Western states and companies to distance themselves from the kingdom.

Saudi allies are putting pressure on Riyadh to come clean about the fate of Khashoggi.

US President Donald Trump suggested "rogue killers" could be behind the disappearance of Khashoggi following talks with Saudi King Salman.

According to The New York Times, Saudis are now trying to develop a scenario that would shield Bin Salman from involvement in the embarrassing drama.