US military officials are worried about the increasing use of chemical bombs in Iraq.Insurgents yesterday exploded a truck carrying chlorine gas canisters â€“ the second such â€œdirtyâ€ chemical attack in two daysÂ â€“ while ground fire apparently forced the downing of a Black Hawk helicopter. All nine aboard the aircraft were rescued.
Thunderous explosions reverberated through Baghdad after midnight as the security crackdown in the capital entered its second week.
Military officials worry extremists may have recently gained more access to firepower such as shoulder-fired anti-aircraft rockets and heavy machine guns – and more expertise to use them. The Black Hawk would be at least the eighth US helicopter to crash or be taken down by hostile fire in the past month.
The gas cloud in Baghdad, meanwhile, suggests possible new and co-ordinated strategies by bombers trying to unleash toxic â€“ and potentially deadly – materials. â€œTerrorists are using dirty means,â€ said Brig. Gen. Qassim Moussawi, an Iraqi military spokesman.
In Baghdad, a pick-up truck carrying chlorine gas cylinders was blown apart, killing at least five people and sending more than 55 to hospitals gasping for breath and rubbing stinging eyes, police said.
On Tuesday, a bomb planted on a chlorine tanker left more than 150 villagers stricken north of the capital. More than 60 were still under medical care yesterday. Chlorine causes respiratory trouble and skin irritation in low levels and possible death with heavy exposure.
In Washington, two Pentagon officials said the tactic had been used at least three times since January 28, when a truck carrying explosives and a chlorine tank blew up in Anbar province. More than a dozen people were reported killed.
A third Pentagon official said the United States has been concerned about Iraqi militantsâ€™ ability to get weapons such as chlorine bombs and use them effectively. But the official cautioned that chlorine bombs were just one threat on a long list of possible attacks that Iraqi fighters may try to carry out.
Patrick Lang, a former official at the Defence Intelligence Agency, said the insurgents were always â€œseeking to achieve higher levels of effectivenessâ€ and these new tactics are part of the normal â€œevolution of sophisticationâ€.
Mr Lang said trucks filled with chlorine gas are â€œreally quite deadlyâ€ because the gas was potent and spread easily.
Some authorities believe militants could be trying to maximise the panic from their attacks by adding chlorine or other noxious substances.