A Libyan official quit his job on Wednesday highlighting tensions in the security establishment after a deadly attack killed four Americans, including the ambassador, in Benghazi. \"There are problems at the ministry of interior and disputes between the security services,\" Fawzi Wanis al-Kadhafi, head of the supreme security committee in Benghazi, told AFP. \"Working conditions are not the same as before, so I decided to resign,\" he added. The supreme security committee, which falls under the interior ministry, was established by ex-rebels after the overthrow of Moamer Kadhafi last year in a bid to restore order. Libya\'s interior minister on Monday announced the sacking of deputy interior minister for the eastern region, Wanis al-Sharef, and the head of national security for Benghazi, Hussein Bou Hmid. The resignation comes a week after Ambassador Chris Stevens and three other Americans were killed as the Benghazi consulate came under fire from rocket-propelled grenades. The attack was orginally blamed on protesters angered by an anti-Islam film made in America but neither US or Libyan officials have excluded the possibility that it was a pre-planned attacked supported by Al-Qaeda.