ISTANBUL (Reuters) – The Nobel Peace Prize winner Tawakkol Karman called on the international community to press Saudi officials for the journalist's disappearance after he entered the kingdom's consulate in Istanbul.

"If [Jamal] Khashoggi is detained, we demand his immediate release," Karman said.

"The Saudi regime's intelligence is responsible," she said, vowing not to "be silent about what happened to Khashoggi."

Khashoggi, a Washington Post journalist and writer, has disappeared since entering the consulate on Oct. 2.

The Turkish police investigating the case said in a statement Saturday that 15 Saudis, including several officials, arrived in Istanbul aboard two planes and entered the consulate while Khashoggi was inside.

Prosecutors in Istanbul are investigating the incident, while the Saudi consulate on Twitter said it was working in coordination with the Turkish authorities.

Turkey said on Monday it expected "full cooperation" from Saudi authorities to locate the missing journalist.