More chemicals found at Uzbek base

Deadly nerve agents and mustard gas were identified earlier in three areas of the Karshi Khanabad station in Uzbekistan.

The latest discovery could be a blood agent such as cyanide, which stops cells in the blood absorbing oxygen.

All troops have been moved away from the affected areas though a military spokesman said there was no confirmation the newest find did indicate the presence of more chemical weapons.

Colonel Roger King said further tests were needed on the traces, which could actually be rocket fuel as that has a similar composition to some types of blood agents and has caused confusion in past tests.

About 1,000 American military personnel are stationed at the air base which they call K2 and which is being used as the logistics centre for the operation in Afghanistan.

Colonel King said: "Medical surveillance of all personnel at K2 continues and we still have no reported cases of chemical agent exposure."

Sensors deployed

A routine inspection of the base had turned up three areas of contamination.

Officials said the traces may have come from chemical weapons believed to have been stored at Karshi Khanabad when it was a Soviet base.

Though a test last year detected no dangers, warm weather may have caused the release of new vapours, according to one theory.

It was also possible that chemical weapons were buried under the site and were now leaking, a military official said.

Tests are continuing and sensors have been placed around the base to monitor any spread of dangerous gases.