Safety rules governing flights in UK and Irish airspace have been eased following the Iceland volcano, the Civil Aviation Authority has announced.

It said it had cleared the way for more flights by lifting the 60-mile no-fly buffer zone imposed around dense ash.

Passengers, meanwhile, have been facing more disruption as the ash forced parts of Spain, Portugal, Morocco and the Canary Islands to close their airspace.

UK airports remain open, but dozens of flights were cancelled and delayed.

A CAA spokesman said its decision to remove the buffer zone was taken with the Irish Aviation Authority after three weeks of evidence gathering.

He said: "Following in-depth and evidence based studies a larger amount of air space can now be allowed to remain open when there are very small amounts of volcanic ash at acceptable levels in the atmosphere.

Long delays

"This will reduce the impact of volcanic ash on airports, and ease some restrictions on flight operations, enabling more flights to resume."

The CAA, the UK's safety regulator, said its goal is to allow as much flying as safely possible.

But both Ryanair and Easyjet confirmed they had been forced to scrap flights to Europe as the problems from the Eyjafjallajokull volcano continued.

Airlines and airports urged passengers to check updated information before travelling.

London's two main airports both reported a handful of cancellations - 19 arrivals and 17 departures at Gatwick, and seven arrivals and four departures at Heathrow.

A Gatwick spokesperson also said 20 arrivals and 25 departures out of the 688 flights scheduled on Tuesday had been delayed by the ash.

Ryanair said it had cancelled flights to and from the Canary Islands, Faro and Madrid.

Flights to and from Granada, Jerez, Malaga, Seville and Tangier have also been cancelled.

Easyjet spokesman Andrew McConnell said the "vast majority" of its flights were operating normally.

Passengers travelling to and from Madrid, Faro, Funchal, Marrakesh and Tenerife should check their flight status before travelling, he said.

British airports operator BAA has also warned of delays to transatlantic services and cancellations by airlines.

British Airways and Virgin Atlantic are among the carriers whose passengers suffered long delays on Tuesday.

Last month, ash from the Iceland volcano shut down airspace across Europe for five days.

British tourism operator TUI Travel estimated the travel chaos caused by the volcanic ash cloud had cost the group £90m.

Gatwick said the impact on last month's passenger figures was severe.

It said it handled a total of 2.05m passengers in April, a drop of 586,000 - more than a fifth - on the same month the year before.