(CBS NEWS) -- An American teacher working at an international school in the eastern Libyan city of Benghazi was shot and killed Thursday, a school official confirmed to CBS News.
Ronald Smith, a chemistry teacher at the International School Benghazi, was jogging at the time of the attack, according the official.
"He was doing his morning exercise when gunmen just shot him. I don't know why. He was so sweet with everyone," Adel al Mansouri, director at the school in Benghazi, told Reuters.
The U.S. Embassy in Tripoli confirmed a U.S. citizen was killed and said it was in touch with the next of kin.
It was not immediately clear who was responsible for the killing.
Libyan special forces have been battling militants from Ansar al-Sharia in Benghazi. U.S. officials blame the group for attacking the U.S. consulate in the eastern city in September 2012, killing the ambassador and three other Americans.
Security sources said three soldiers were also killed in separate attacks on Thursday in Benghazi.
Two years after a NATO-backed uprising ousted veteran leader Muammar Qaddafi, Libya's armed forces are struggling to contain militias, former fighters and Islamist militants who control parts of the vast oil-producing country.