British "Undercover Soldiers" Caught driving Booby Trapped Car - "They refused to say what their mission was."

The following Reuters report raises some disturbing questions.

Why were undercover British "soldiers" wearing traditional Arab headscarves firing at Iraqi police?

The incident took place just prior to a major religious event in Basra.

The report suggests that the police thought the British soldiers looked "suspicious". What was the nature of their mission?

Occupation forces are supposesd to be collaborating with Iraqi authorities. Why did Britsh Forces have to storm the prison using tanks and armoured vehicles to liberate the British undercover agents?

"British forces used up to 10 tanks " supported by helicopters " to smash through the walls of the jail and free the two British servicemen."

Was there concern that the British "soldiers" who were being held by the Iraqi National Guard would be obliged to reveal the nature and objective of their undercover mission?