Updated

Israel's military says troops arrested the brother of a senior member of the Islamic militant group Hamas.

It said Wednesday that Bilal Rozayna, the brother of Hamas internal security chief Mustafa Rozayna, was arrested last month after he entered Israel.

It said he "revealed sensitive information regarding Hamas activity" about the group's tunnel system and use of civilian areas in the 2014 war with Israel, including a hospital.

Hamas is trying to rebuild its vast underground network of tunnels — designed to store weapons and infiltrate Israel — which was damaged in the 2014 war.

There was no immediate comment from Hamas.

Hamas seized Gaza in 2007 after driving out forces loyal to Palestinian President Mahmoud Abbas. It has fought three wars with Israel since then.