Al-Qaida tapes show chemical experiments on dogs

US TV network CNN has begun airing excerpts from a cache of video tapes acquired in Afghanistan that purport to show al-Qaida terror training, bomb-making and poison gas experiments on dogs.

The tapes also show al-Qaida operatives apparently practising ambushes and kidnapping.

Most tapes appear to be made before September 11, although some show recorded television coverage of the last of the attacks in New York and Washington.CNN said correspondent Nic Robertson acquired more than 250 tapes through a source, and he drove 17 hours from Kabul to a remote part of Afghanistan to first see them.