Oil companies must make better plans to keep supplies moving out of Grangemouth in the event of a flu pandemic, it has emerged after an emergency planning exercise.

Schools also have to be better prepared to fill vacancies once teachers begin to go off work with illness.

There were also concerns about stockpiles of anti-viral drugs if such an outbreak took hold and spread rapidly.

The recommendations were included in a report on Operation Winter Willow, a test of pandemic emergency plans across government and emergency services that was carried out last January and February.

The report, published by the Scottish Executive as part of a UK-wide exercise, says more should be done to improve communications between different organisations. It found that daily video-conferencing between national level and health boards proved particularly useful.

The concerns around shortages of anti-viral drugs are being addressed with a review of current planning, and new priority groups are being identified, with an announcement at UK level by June next year.

The specific Scottish issues identified by Operation Winter Willow included fuel supplies, school closures, recovering planning for backlogs of routine work and the importance of keeping the Scottish Parliament operating. Holyrood officials have begun plans to make sure it is not forced to close by staff shortages.

"The exercise showed that maintaining business continuity will be a significant challenge to all organisations during a flu pandemic," said the report. "Specific business continuity issues identified included the consequences of staffing shortages at major fuel depots such as Grangemouth."