A fire that destroyed 130 hectares of heathland near Ede in Gelderland on Thursday was caused by a smoke grenade used during army exercises.

The grenade was used in a sandy area but ended up on the heath instead and the ensuing fire quickly spread, boosted by strong winds. An area of 130 hectares, or 260 football pitches, between Koedijk and the Ginkelse Heide nature reserve have now gone up in flames.

The fire broke out at 2.45 pm on Thursday afternoon, and it took some 500 firemen recruited from several services in the area to douse the main flames by around 8.30 pm.

However, it will take all day Friday to tackle so-called hot spots where the fire has gone underground, a fire department spokesman said. The N304 between Ede and Otterlo remains closed.

“Unfortunately, a large area has been affected by the fire,” the deputy mayor of Ede, Arnold Versteeg said. “It has had a big impact. A lot of valuable and cherished nature has been lost,”  he told local broadcaster Omroep Gelderland.

The military police have started an investigation to determine if safety rules were observed and if there was more than one fire source.

The risk of wildfires and water shortages in the Netherlands has increased following the driest winter in nearly 30 years.

Around 80 forest fires were reported in March, nine times as many as last year, which was one of the wettest starts to the year on record.

The website Natuurbrandenrisico.nl has put the provinces Noord-Holland, Zuid-Holland and Noord-Brabant on “phase 2” alert, warning landowners and responders to be extra alert.

Parts of Noord-Brabant have also brought in a sprinkler ban.