Airlines began cancelling flights to Britain late on Monday because of an ash cloud from an Icelandic volcano reaching its airspace, although experts expected no repeat of travel chaos from an eruption a year ago.

Britain's Met Office forecast the plume of ash from the Grimsvotn volcano would cover the Irish Republic, Northern Ireland, Scotland and parts of northern England by 0600 GMT on Tuesday.

Worries about the effect of the ash cloud pushed forward US President Barack Obama's planned departure from Ireland and he arrived on Monday night in Britain to begin a state visit.

The Irish Aviation Authority said flights to and from Ireland could be disrupted later in the week but did not expect problems in the next 48 hours. Iceland's main airport reopened late on Monday, while other parts of Europe were on alert.

With the ash cloud approaching, airlines began cancelling flights over the UK, raising the spectre of big losses for airlines already facing sky-high fuel costs.

British Airways grounded all flights from London to Scotland until 2 pm (1300 GMT) on Tuesday as a precautionary measure, a spokeswoman said.

Flybe, EasyJet and Aer Lingus all said they were cancelling some of their flights to and from Scotland on Tuesday.

Dutch airline operator KLM, part of Air France-KLM, said on Monday night it had cancelled 16 flights flying to and departing from four British cities and scheduled for Tuesday. Fights to and from Aberdeen, Glasgow, Edinburgh and Newcastle would be cancelled on Tuesday morning, it said.

Iceland's aviation authority reopened Keflavik airport late on Monday, but said it was impossible to know whether the island's international hub would remain open on Tuesday.

'It is open now,' spokeswoman Hjordis Gudmundsdottir said. 'We will know tonight or tomorrow morning how it will go.'

Last year, ash from an Icelandic volcano caused 100,000 flights to be cancelled, stranding 10 million passengers and costing the industry an estimated $1.7 billion in lost revenue.

Asked earlier on Monday if the ash cloud would cause some disruption to flights this time, a spokesman for Britain's Civil Aviation Authority said: 'That's the way it's looking certainly at the moment.'

Europe's air traffic control organisation said that if the volcanic emissions continued at the same rate, the cloud could reach western French and northern Spanish airspace on Thursday.

Asian airlines ‘unaffected’

Asian airlines were operating flights to Europe as normal on Tuesday but said they were closely monitoring an erupting Icelandic volcano after some European airlines earlier cancelled flights to Britain.

China Southern Airlines operates daily passenger flights to Amsterdam and Paris and said so far its flights have not been affected.

'Everything is normal for the time being, but we are closely watching the situation. We cancelled flights to Europe for two day last time where there was a volcano explosion,' said Shao Fuqiang, a spokesman with China Southern Airlines.

Other airlines began cancelling flights to Britain late on Monday because of an ash cloud from the Grimsvotn volcano reaching its airspace, although experts expected no repeat of the travel chaos that resulted from an eruption a year ago. – Reuters