DUBAI (Reuters) - The United Nations mission in Libya (UNSMIL) called on Saturday for the immediate release of a journalist detained in Tripoli two days ago, adding all media workers should be kept safe.

UNSMIL said it was concerned by "the arbitrary arrest and detention of journalist Ahmed Sanussi on 11 July".

Sanussi is the general manager of internet channel Tabadul and the presenter of "Flousna" ("Our Money"), a TV programme on the Tunisia-based Wasat TV channel, according to his verified Facebook page.

Sanussi's channel and programme mainly focus on economic and social issues.  

"Stifling journalists' reporting fosters a climate of fear and undermines the environment needed for Libya's democratic transition," the mission said.

Oil-rich Libya plunged into chaos following the toppling of long-time ruler Muammar Gaddafi in a NATO-backed uprising in 2011.

In a briefing to the U.N. security council in mid-June, U.N. deputy representative Stephanie Koury said she was concerned "by the reports of violations throughout the country, particularly the repetitive pattern of abduction or arbitrary arrest and detention of Libyans."

(Reporting by Tala Ramadan; Editing by Mark Potter)