ANKARA (Reuters) - Turkey’s foreign ministry has summoned Saudi Arabia’s ambassador for consultations over the disappearance of journalist Jamal Khashoggi after he entered the Saudi consulate in Istanbul, Turkish sources said on Thursday.

Saudi dissident Jamal Khashoggi speaks at an event hosted by Middle East Monitor in London Britain, September 29, 2018. Middle East Monitor/Handout via REUTERS

They said the Saudi envoy was called in on Wednesday to clarify the whereabouts of Khashoggi, a critic of Riyadh’s foreign policy and its crackdown on dissent who left Saudi Arabia last year saying he feared retribution for his views.

“Yesterday the Saudi ambassador was summoned to the foreign ministry and the issue of Khashoggi was discussed,” one of the sources said. “Efforts are being made to clarify allegations about Khashoggi. We believe a positive outcome will emerge.”

He said contacts were continuing to “overcome the problem”.

The source gave no further details but Turkish broadcaster NTV said the ambassador told Turkish officials he had no information about Khashoggi. Turkey’s Deputy Foreign Minister Yavuz Selim Kiran told the Saudi envoy that the issue “should be cleared up immediately,” NTV said.

Khashoggi’s fiancée and a close friend said he vanished after entering the Saudi mission in Istanbul on Tuesday.

Saudi Arabia’s Consulate General in Istanbul said in a statement on Wednesday that Khashoggi had left the consulate building shortly after his appointment on Tuesday.

It said the consulate was working with Turkish authorities “to uncover the circumstances” of his disappearance. No one at the Saudi embassy in Ankara was available to comment on Thursday and an official at the consulate, asked about the envoy’s summons, referred back to the statement.

The Saudi Foreign Ministry said in a tweet that its Undersecretary for Political and Economic Affairs Adel Merdad held talks in Riyadh with Turkey’s ambassador Erdogan Kok.

Khashoggi’s disappearance could complicate already fraught ties between Ankara and Riyadh. Turkey has supported the Gulf state of Qatar in its prolonged stand-off with Saudi Arabia and its allies, sending troops to Qatar last year.

President Tayyip Erdogan’s spokesman said on Wednesday Turkey believed Khashoggi was still inside the Saudi consulate in Istanbul, challenging the Saudi account.

However, Turkey has avoided public criticism of Saudi Arabia, which is a regional economic power due to its oil wealth and which is also the home of Islam’s two holiest shrines.