The new volcanic ash cloud is expected to result in the loss of 1,000 flights in Europe on Monday with airports across Holland closed, the Eurocontrol agency said.

However the cloud was expected to disperse during the day, Europe’s intergovernmental air traffic coordinating agency said.

“On Monday Eurocontrol expects 28,000 flights in Europe. This is approximately 1,000 less than on a normal day, and is due to the expected impact of the current closure of airspace in the south-east of the UK and in the Netherlands,” it said.

“The areas of ash concentration are mainly at low levels. During the course of the day, the current cloud is expected to disperse somewhat,” it said in one of its regular updates.

The ash cloud forced the closure of Amsterdam’s Schiphol airport and those in Rotterdam and Groningen until 2:00 pm (1200 GMT) Monday, Dutch officials said.

London’s main airports Heathrow and Gatwick reopened Monday after being forced to close overnight by the ash cloud billowing from the Eyjafjoell volcano in Iceland, but other British airports remained shut.

The volcanic dust at more concentrated levels presents a danger to plane engines, though some industry officials have complained that the safety measures and airport closures have been excessive.

Europe’s skies were partially closed for up to a week in April following the eruption of Iceland’s Eyjafjoell volcano, in the biggest shutdown of the continent’s airspace for more than 50 years.

Experts fear the volcanic ash can damage jet engines and create a serious risk of a crash.

On Sunday, Eurocontrol said, disruptions in Ireland and the north-west of Britain resulted in a loss of some 400 flights.