Hundreds of flights at airports from Lisbon to Munich were cancelled Sunday and some European airspace was closed because of a volcanic ash cloud from Iceland that caused air travel chaos last month.

All flights to the city of Porto in northern Portugal and the Azores were suspended, with normal operations expected to resume by 0600 GMT Monday, airport officials there said.

In all more than 200 flights were grounded in Portugal, including 71 at Lisbon's airport, where Pope Benedict XVI is due to arrive on Tuesday for a four-day visit to the country.

The Vatican said Sunday the pope's trip was still on schedule despite the air traffic disruptions.

"At the present time, we expect no change to the programme" of the pope's visit, Vatican spokesman Federico Lombardi told AFP.

The volcanic ash cloud's unwelcome return affected air travel across much of southern Europe, especially in France and Italy, and extended into Austria and Germany.

The airspace around the southern German city of Munich was closed at 1300 GMT, cancelling flights there and at other airports including Stuttgart, but DFS air safety agency said Munich airport, Germany's second busiest, would reopen at 2100 GMT.

Airport officials told AFP that 460 take-offs and landings had been cancelled at Munich on Sunday out of more than 1,000 scheduled movements. Fifteen delayed long-distance flights would take off after the airport reopens, said a spokesman.

DFS also gave the green light for two regional airports to reopen at 2000 GMT. Stuttgart was back in business at 1600 GMT.

The German weather service DWD said it expected the cloud to move over central Germany overnight Sunday and the rest of the country during Monday, with no more ash disruption from Tuesday.

Southern Czech airspace was closed late Sunday but the airport of the capital Prague was not affected, aviation authorities said.

Neighbouring Austria also partially closed its airspace until the early hours of Monday, hampering traffic at airports in Vienna, Innsbruck, Linz and Salzburg, the air authority Austro Control said.

The coordinator of air traffic control across Europe said it expected about 24,500 flights to take place on Sunday, around 500 less than the average for this time of year.

Eurocontrol added that "transatlantic flights continue to be affected by the ash cloud", with many suffering delays as they skirt the edges of the volcanic plume.

Authorities reopened Italy's skies in the north to air traffic at 1400 GMT after shutting down its airspace earlier for about six hours as the ash cloud hovered over the peninsula, cancelling nearly 300 flights at Milan airports.

On Croatia's Adriatic coast the ash cloud forced officials to close airports at Split and Zadar at 1200 GMT.

In France, the airspace remained open Sunday but at least 100 flights bound for southern Europe were grounded at airports in Paris, Lyon, and Nice, the nearest international airport to Cannes which is to host its flagship international film festival in three days' time.

The French weather service Meteo-France warned that the volcanic ash cloud could drift over southern France by Monday morning and that it could continue to affect Europe's skies for several months.

Late Sunday, Meteo-France said that fresh rainfall was expected Monday which it said was "rather good news" as it would help disperse the ash.

Iceland's Eyjafjoell volcano erupted on April 14 and caused travel chaos worldwide with airspace closed over many European nations for a week in mid-April for fears the ash would damage aircraft engines with fatal results.

It was the biggest aerial shutdown in Europe since World War II, with more than 100,000 flights cancelled affecting some eight million passengers. The airline industry said it lost about 2.5 billion euros (3.2 billion dollars).

The volcano began fresh and intensive ash eruptions overnight Thursday and closed Ireland's airspace for a time, and was again affecting the island nation on Sunday.

Irish airports at Donegal, Sligo and Ireland West (Knock) on the western coast faced restrictions from 1400 GMT Sunday while Galway would be disrupted from 1500 GMT and Kerry from 2100 GMT, authorities said.

Meanwhile, Spanish air traffic was returning to normal with most of the 19 airports in northern Spain that were closed on Saturday reopening around 1400 GMT, air control authority Aena said.

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