The State Department probed Israel's use of cluster bombs in civilian areas of southern Lebanon during the 34-day conflict with Hezbollah.

US-made weapons are sold to the Israeli military with restriction on their use.

Cluster bombs can scatter hundreds of small bomblets over a wide area, and their use has been widely criticised.

The US government has now sent a preliminary report on its investigation into the matter to the US Congress.

The International Committee of the Red Cross called for a ban on the use of cluster bombs in populated areas, because of the indiscriminate civilian deaths they caused.

And Amnesty International has criticised Israel for its use of cluster bombs in the final days of the conflict.