A large explosion rocked Beirut on Tuesday, injuring many people as glass shattered and balconies collapsed from the impact, Reuters witnesses said. Lebanon's state news agency NNA and two security sources said the blast had occurred in the port area where there are warehouses housing explosives. It was not immediately clear what caused the blast or what kind of explosives were in the warehouses. People were screaming and running, bleeding. Balconies were blown off buildings. Glass in high-rise buildings shattered and fell to the street," said a local broadcaster quoting the health minister as saying there was a "very high number" of injures and a large amount of damage. Another local television said hundreds were wounded. Heavy grey smoke near the port area was seen by an eye witness, according to Reuters, and then an explosion was heard with flames of fire and black smoke.