Reykjavik/London/Brussels, May 17 (DPA) An ash cloud from an Icelandic volcano Monday grounded some 1,000 flights in Europe and forced the temporary closure of several main airports in Britain and the Netherlands.

“Today Eurocontrol expects 28,000 flights in Europe. This is approximately 1,000 less than on a normal day,” Europe’s air safety agency, Eurocontrol, said.

In Britain, London’s two main airports, Heathrow and Gatwick, reopened to normal traffic late Monday morning (1100 GMT) after overnight closures as knock-on delays continued to affect passengers.

A no-fly zone was to remain in place in two key regional areas, affecting operations in Northern Ireland and the Shetland Isles off the north-east coast of Scotland.

The two biggest airports in the Netherlands, Amsterdam and Rotterdam, also reopened in the early afternoon after being closed Monday morning.

The Spanish airport authority Aena said 140 flights were cancelled from Spain to Britain, the Netherlands and Ireland.

The continuing ash output of the Icelandic volcano last month started disrupting flights in and out of Europe, causing major economic and logistical havoc.

British Airways (BA) chief Willie Walsh Monday criticised the latest closure of airspace due to the ash cloud from Iceland.

Walsh said the bans imposed by Britain’s air traffic control services were a “gross overreaction to a very minor risk”.

Icelandic authorities meanwhile said there were no signs of change in activity at the volcano located some 120 km south-east of the capital, Reykjavik.

Weather forecasts suggested winds would change in the coming days, blowing the ash to the north of Iceland and away from Britain and mainland Europe.

Eurocontrol said the ash cloud would “disperse somewhat” over the course of the day. By 1200 GMT it was expected to move away from the Netherlands and “to mainly affect Northern Ireland, parts of Scotland and parts of south-west (England)”.