A rocket was fired from south Lebanon towards Israel on Sunday, Lebanese security sources said, and residents of a northern Israeli town reported hearing a blast.
"An explosion was heard. Soldiers are searching the area. The cause is still being investigated," an Israeli military spokeswoman said. A second Israeli military source said the explosion was probably caused by a mortar.
The incident came amid heightened tensions in the region over Syria's civil war. Damascus has said it will respond to Israeli air strikes earlier this month against suspected Iranian missiles in Syria destined for the Lebanese militant group Hezbollah.