Brussels, April 19 (DPA) The cloud of volcanic ash over Europe is beginning to thin and a number of countries have been able to reopen their airspace, European air traffic control body Eurocontrol said Monday.

The cloud from an Icelandic volcano has forced the widest and most expensive shutdown in European aviation history, with experts saying that it dwarfs the closures which followed the terrorist attacks on New York and northern Virginia Sep 11, 2001.

But according to Eurocontrol, the cloud thinned significantly in the night from Sunday to Monday, especially around the Mediterranean and in Scandinavia.

Spain, Portugal, southern France, northern Italy and Slovenia were all ash-free Monday morning, as were Norway and parts of Sweden and Finland, Eurocontrol said. Poland and Belarus were also clear.

Sunday, the cloud had blanketed the overwhelming majority of European airspace from northern Norway to Mallorca and from Ireland to Turkey.

However, with the volcano under Iceland’s Ejyafjallajokull glacier still erupting, officials said it was not clear whether the break in the cloud heralded its dissolution or was just a temporary respite.