A Libyan air force officer was killed and another security forces member badly wounded on Sunday in two separate attacks in the eastern city of Benghazi, an official said.
"Unidentified assailants opened fire on Abdelfattah al-Ryani, an air force officer, in the Al-Hadaek region of Benghazi," Colonel Abdullah al-Zaidi of the security services told AFP.
The officer "died after being struck by bullets in the head and chest", he added.
In the other attack, Abdessalam al-Dursi, a colonel in a police anti-drugs unit, was gravely wounded when a bomb planted in his car exploded.
Officials at Benghazi's Al-Jala hospital said Dursi suffered serious leg injuries and that his condition was "critical".
Benghazi, the cradle of the 2011 uprising that ousted former dictator Moamer Kadhafi, has seen a series of assassinations targeting officers in the security services.
Other attacks have targeted Western interests and diplomats, and much of the violence, including the killing of US ambassador Chris Stevens last year, has been attributed to radical Islamists.