LONDON - Volcanic ash blanketed parts of rural Iceland on Friday and left a widening arc of grounded aircraft across Europe, as thousands of planes stayed on the tarmac to avoid the hazardous cloud. Eurocontrol, the European air traffic agency, said the flight disruptions that upended travel in Europe and reverberated throughout the world Thursday were even worse on Friday. Half a dozen European nations have closed their airspaces, the cloud was drifting east, about 60 percent of European flights were not operating and delays will continue into Saturday, it said. "We expect around 11,000 flights to take place today in European airspace. On a normal day, we would expect 28,000," said Kyla Evans, a spokeswoman for Eurocontrol. "The cloud of volcanic ash is continuing to move east and southeast." Ice chunks the size of houses tumbled down from a volcano beneath Iceland's Eyjafjallajokull (ay-yah-FYAH'-plah-yer-kuh-duhl) glacier Thursday, as hot gases melted the ice. The volcano began erupting Wednesday for the second time in less than a month. As torrents of water roared down the steep slopes of the volcano, about 40 people nearby were evacuated because of flash flooding. More floods from melting waters are expected as long as the volcano keeps erupting, said Rognvaldur Olafsson of the Civil Protection Department. The ash cloud, drifting between 20,000 to 30,000 feet (6,000 to 9,000 meters) high and invisible from the ground, left tens of thousands of travelers stranded around the globe and blocked the main air flight path between the US east coast and Europe. Trains and hotels in key European cities were packed as people scrambled to make alternate travel plans. Fearing that microscopic particles of highly abrasive ash could endanger passengers by causing aircraft engines to fail, authorities shut down air space over Britain, Ireland, France, Denmark, Norway, Sweden, Finland and Belgium. That halted flights at Europe's two busiest airports ��" Heathrow in London and Charles de Gaulle airport in Paris ��" as well as dozens of other airports, 25 in France alone. As the cloud moved east, flights were halted Friday at Frankfurt airport, Europe's third-busiest terminal, and at 10 other German airports including Duesseldorf, Berlin, Hamburg and Cologne. No flights were allowed at the Ramstein Air Base, a key U.S. military hub in southwestern Germany. No more than 120 trans-Atlantic flights reached European airports Friday morning, compared to 300 on a normal day, said Eurocontrol's Evans. About 60 flights between Asia and Europe were canceled Friday, stranding several thousand passengers. As the cloud moved to the south and east, some European countries reported a slight easing of conditions. The French Civil Aviation said it will allow some planes to land at the three Paris airports during a four-hour window starting at noon Friday. Sweden and Norway declared skies in the far north to be safe again for travel even as flights in both capitals ��" Stockholm and Oslo ��" were still on a lockdown. Aviation authorities in Ireland reopened airports in Dublin and Cork and lifted most restrictions on the country's airspace.