Hizbollah is training its militia to be able to hit Tel Aviv with long-range missiles, and has stockpiled 40,000 rockets on the border, a report by The Times claimed.
A Hezbollah warehouses which stored Katyusha rockets in southern Lebanon exploded last month, revealing the group was stockpiling rockets in the region, in violation of the UN Security Council Resolution 1701.
UN peacekeeping forces have been blocked from entering the site to investigation the claims.
There has been little breach of the peace since the 2006 Israeli-Lebanese conflict but tensions in the region are now running high.
In June, Hezbollah secretary general Hassan Nasrallah predicted that Israel would attack the Hezbollah strongholds by the spring, and warned that this would lead to an attack by Hezbollah on Tel Aviv.
Senior figures in the IDF have said they are taking the threat extremely seriously.