Europe's air traffic returned to normal Thursday after more disruption due to volcanic ash from Iceland, but re-routing of transatlantic flights is being discussed, the Eurocontrol coordinator said.

All scheduled 28,500 flights were set to operate in Europe's airspace as airports in Ireland and Britain fully re-opened Thursday after the latest shutdown caused by the Icelandic volcano that sparked travel chaos last month.

The area where concentrations of ash could still pose a risk to plane engines was lying to the north and west of Ireland, the intergovernmental air traffic controller Eurocontrol said.

However "significant re-routing of westbound transatlantic flights to avoid the higher contaminated area is currently being discussed between the air navigation service providers concerned and Eurocontrol," the Brussels-based body said.

Travellers in Scotland, Northern Ireland and Ireland were left stranded on Wednesday by the cancellation of hundreds of services.

The fresh disruption came after Europe's skies were closed for up to a week last month by the eruption of the Eyjafjoell volcano. It was the biggest aerial shutdown in Europe since World War II, with more than 100,000 flights cancelled and eight million passengers affected.

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