Al-Qaeda videos showing Iraqi children carrying out mock kidnappings and attacks have been seized by US forces.

Five videos, featuring children mostly under the age of 11, were found during an operation against the Sunni Islamist militants.

The footage showed about 20 boys wearing balaclavas, and brandishing AK-47 assault rifles and rocket-propelled grenade launchers almost as big as themselves.

"This is not the first time we've observed such material but the volume and content was the most significant and disturbing we have found to date," said US military spokesman Rear Admiral Gregory Smith.

He said the videos were meant to spread al-Qaeda's message among the young rather than train the boys for missions.

The US military did not know exactly where or when the films were made, or how many children were involved.

Other seized pictures showed a young boy wearing a "suicide vest", while US soldiers had also found a written proposal for a movie script about training children for warfare.

Rear Admiral Smith said: "The script was to include children interrogating and executing victims, planting improvised explosive devices and conducting sniper attacks."

He said there had been two recent suicide bombings by 15-year-old boys, while the number of attacks involving women had also increased.

Last week two women blew themselves up at popular pet markets in Baghdad, killing 99 people.

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