Flights to and from Europe started to resume Monday as the European Union decided to free up airspace, giving relief to passengers stranded around the world in a historic travel chaos following a volcanic eruption in Iceland Wednesday.

Although authorities predicted that flights over the European continent could be running normally again by Thursday, there were worries about new disruptions after British air traffic officials observed a fresh cloud of ash spreading toward Britain.

On Monday, EU transport ministers announced an easing of restrictions from Tuesday. EU Transport Commissioner Siim Kallas expected to "progressively see more planes start to fly from tomorrow (Tuesday) on" while Europe's air traffic control group Eurocontrol predicted flights over Europe back to normal operation by Thursday.

Starting from Monday some countries had already moved to resume some flights.

Germany's international airports saw some movements Monday as the country's air control authority granted airlines permission for a limited number of flights, which will fly under special rules to avoid possible hazards from volcanic ash.

The biggest German airline Lufthansa announced that it had obtained special permission for 50 long-haul flights to bring back about 15,000 German travelers stranded overseas.

Three KLM flights carrying passengers left Amsterdam-Schiphol airport Monday for Shanghai, Dubai and New York, the Dutch transport minister announced.

France said it was progressively reopening airports from Monday, with restricted flights from Paris to start from early Tuesday.

Britain announced that it would partially reopen airspace from 0600 GMT Tuesday.

Authorities in Sweden, Croatia, Hungary and the Czech Republic also announced the resumption of flights. Romania and Bulgaria announced that their airspace had been reopened, while Switzerland said its airspace would reopen early Tuesday.

Elsewhere around the world flights bound to Europe have also started to resume. Early Monday in New York check-in was underway for three flights headed to Paris, along with two to Moscow and at least one flight each to Munich, Vienna and Istanbul.

Los Angeles International Airport (LAX) officials said five Europe-bound flights were expected to depart later Monday. The British Airlines and Lufthansa Airlines each planned two flights, and Air Tahiti Nui planned one, they said.

However, a new cloud of volcanic ash has been observed from the Icelandic volcano at the source of the chaos, creating fears of more disruptions to flights.

British air traffic officials said Monday the ash was heading toward Britain, pledging flexible plans to adjust to the rapidly changing conditions due to the unpredictability of the volcano.

Wednesday's volcanic eruption has led to an almost complete shutdown of European airspace for the past four days, affecting nearly 7 million passengers and sending the air industry already struggling in the aftermath of the financial crisis to a more miserable situation.

Companies are losing 270 million U.S. dollars per day, according to the International Air Transport Association (IATA).

Although officials have justified the widespread airport closures by saying that airplane engines could become clogged up and stop working if they tried to fly through the ash, airlines have criticized the sweeping measures as unnecessary, saying they caused chaos and massive financial losses.

The current spate of volcanic eruptions from under Iceland's Eyjafjallajokull glacier started Wednesday. The ash has been covering a wide swathe of Europe and has now even spread across the Atlantic to reach Canada.