An advisor to the Tunisian ambassador in Libya has been kidnapped by unidentified militants in the Libyan capital Tripoli.

An advisor to the Tunisian ambassador in Libya has been kidnapped by unidentified militants in the Libyan capital Tripoli, a Libyan Foreign Ministry source said Thursday.

"The motive for the diplomat's kidnapping remains unknown," he said.

He indicated that the abductee, Al-Arosi Bentati, served as the main advisor to Tunisian Ambassador Ridha Boukadi, adding that the Tunisian embassy in Libya had not yet officially reported the abduction to the Libyan Foreign Ministry.

An official in Tunisia's foreign ministry said: "We cannot confirm that he has been kidnapped but we have been unable to contact him." He said the missing diplomat works as an adviser at the Tunisian embassy in Tripoli.

"Tunisia is worried about Tunisian diplomats getting targeted in Libya," Tunisia's foreign ministry said in a statement. "We ask Tunisians for caution in Libya and to postpone travel to Libya."

The source said Bentati was the second Tunisian diplomat to be kidnapped in Libya within the last month.

On March 20, the Libyan and Tunisian media reported the abduction of Mohamed al-Sheikh, a senior diplomat at Tunisia's embassy in Libyan by militants who demanded the release of detained colleagues held by Tunisia.

On Tuesday, Jordanian Ambassador to Libya Fawaz al-Aitan was also kidnapped along with two companions.

Libya has suffered political and security instability since the overthrow of Moammar Gaddafi in 2011.