UNITED NATIONS, June 16 (NNN-KUNA) -- Expressing "serious concern" over the detention of four staff members of the International Criminal Court (ICC) in Libya, the Security Council on Friday urged the authorities there at all levels and all concerned to work towards their "immediate" release.

The four detained ICC staff members, a Lebanese, an Australian, a Spanish and a Russian, have been detained in Libya since June 7 while visiting Saif Al-Islam Gaddafi in Zintan.

"The members of the Security Council emphasize that it is the legal obligation of Libya under the Council's resolution 1970 (2011) to cooperate fully with and provide any necessary assistance to the ICC pursuant to that resolution," Council President Li Baodong of China said in a statement to the press.

The Council acted upon a request from the ICC which issued a warrant for Gaddafi last year for his involvement in killing protesters during the popular revolt last year.

The Court is urging Tripoli to transfer the late Libyan leader's son to be tried in The Hague. Libya refuses his transfer, saying it will guarantee his fair trial in the country. -- NNN-KUNA