Hezbollah handed over to the Lebanese authorities on Friday the gunman who shot at an army helicopter and killed its pilot, security sources said.
The incident occurred on Thursday over Iqlim al-Touffah region. The area is controlled by the powerful political and military group Hezbollah, which fought a 34-day war with Israel in 2006.
Lebanon's as-Safir newspaper reported that Hezbollah gunmen had targeted the aircraft because they thought it was Israeli. It said the helicopter had landed and taken off again in a training drill. Hezbollah gunmen in the area "thought that there was an Israeli landing attempt (under way) and opened fire in the direction of the helicopter, hitting it", it said.
Hezbollah said earlier in a statement that it would cooperate fully with an investigation into the matter. The group described what happened as a "very tragic and painful incident".
The army said on Thursday the helicopter had made a forced landing after it came under fire from "armed elements". It said the incident was under investigation.
Former prime minister Salim Hoss, who is considered close to the Hezbollah-led opposition, pointed the finger of blame at Hezbollah.
"The area where this distressing incident took place is, as everybody knows, under the control of the Resistance (Hezbollah)," Hoss said.
"Hezbollah must explain and not justify what happened, because the death of a brilliant officer cannot be justified whatever the circumstances of the incident," Hoss said in a statement.