Israeli authorities say they have obtained "high value information" about the Hamas militant group's tunnel network in the Gaza Strip after arresting a 17-year-old fighter.

Israel said Sunday that the teen was nabbed last month after crossing a border fence and entering Israel. It says an interrogation revealed information about his recruitment and training, most of which involved the Hamas tunnels.

Israel says it learned that Hamas' military tunnel network allows it to move fighters throughout Gaza "exclusively underground." The network also includes "rest quarters" for its elite forces.

It says information also was obtained on Hamas' methods for digging tunnels, communications means and the locations of shafts to allow units to infiltrate Israel.

Hamas used tunnels to attack Israel during a 50-day war in 2014.