A reported 20,000 chickens have been killed in an overnight fire at a factory farm in Barneveld, local media said on Saturday.

The fire destroyed four of the five barns at the farm, killing all but a few of the birds.

The cause of the blaze has not yet been established, but, officials say, there maybe a link with the thunderstorm that swept over the south on Friday evening. Lightning is thought to have caused two other fires in the area.

Animal lobby rights group Wakker Dier, which has long campaigned for improvements in farm safety, says that up to last night, 45,000 animals had died in factory farms in the Netherlands so far this year.