Travellers again face flight delays after a cloud of volcanic ash in Iceland stopped several flights to and from Europe.

London's Heathrow Airport was forced to close yesterday morning after ash from Iceland's Eyjafjallajokull volcano drifted south, extending the no-fly zone over Britain.

Airports in other parts of Britain, Ireland and the Netherlands also had to close, although many reopened soon after.

Many flights from New Zealand have been affected - either delayed or diverted to other international airports.

People travelling on Air New Zealand flight NZ2 to London, via Los Angeles, were scheduled to leave the United States for London yesterday.

But because of delays caused by the volcanic ash cloud, travellers were having to stay the night - their flight delayed for 19 hours. The airline provided accommodation.

The Auckland to London flights NZ39 and NZ2 via Hong Kong were still scheduled to leave Auckland Airport last night, but the airline stressed both flights might be delayed if Heathrow remained closed. Flight NZ1, from London, was to leave yesterday but is now due to be rescheduled.

On Cathay Pacific European, six flights were cancelled and three others diverted.

The airline recommended that passengers whose flights had been cancelled not go to the airport, but said "last minute" announcements should be expected, given the nature of the delays.

"We are doing our utmost to provide updated flight information to passengers as soon as possible," an airline spokesman said.

"However forecasts are available only 18 hours ahead and airspace closures are subject to last-minute announcement by the relevant authorities."

Cathay Pacific European said it would waive all fees to cancel, rebook, reroute or refund tickets issued worldwide.

Flights to Asia and North America would not be affected, but passengers with onward flights to Britain and Europe on other airlines were encouraged to check flights frequently.