A Libyan security official says gunmen have shot dead an officer in the air defense branch in the eastern city of Benghazi. The official says Colonel Wanis Massoud al-Barghathi was gunned down Friday night. He didn’t provide further details, and spoke on condition of anonymity because he was not authorized to brief the media. A wave of assassinations and bombings has targeted police and army officers in Benghazi, a stronghold of militias with roots in the rebel brigades that fought against slain dictator Moammar Gadhafi. Some of the groups are Islamic hard-liners with al-Qaida links. © 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed. Learn more about our Privacy Policy and Terms of Use .