The southern Lebanese city of Tyre is now largely cut off from the rest of the world. All bridges out of the city have been destroyed. On Monday, Israel bombed a makeshift bridge that had been set up to cross the Litani River. Doctors Without Borders created a 200-yard-long human chain across the river in order to get aid into the city of Tyre. Aid workers standing in knee deep water passed more than three tons of medical supplies and gasoline across the river by hand. The Guardian newspaper is reporting Israel has also threatened to attack UN peacekeepers if they attempted to repair bomb-damaged bridges in southern Lebanon.