The defence secretary has told MPs that UK military operations in Afghanistan are a success.

In a Commons statement, Geoff Hoon said that while there had been no contact with an enemy, it would be "quite wrong" to portray the mission as a failure.Hoon rejected reports that British troops had only succeeded in destroying munitions of supporters of the interim administration. "This cache belonged to al Qaeda or the Taliban and not to a local warlord," he insisted.

But there was also a warning that "al Qaeda and the Taliban have not completely disappeared".

The mystery illness affecting 18 British troops has led to the suspension of Royal Marines operations in Afghanistan, however.

Hoon also refused to deny reports that members of the SAS are among the 333 troops in quarantine.

The Ministry of Defence played down fears of a biological attack, saying that there "was no evidence to suggest it". However, the cause of the outbreak remains unknown.