An increase in the terrorism threat level is causing headaches for Belgian race organisers as they struggle to increase security.

Belgium is on level three alert for at least the next two weeks, reports Lorenzo Dejonghe of West Flanders television station WTV. That could mean a big increase in the cost of policing the first races of the season.

Kuurne-Brussels-Kuurne on Sunday, March 1 and the Three Days of West Flanders from Friday 5 to Sunday, March 7 are the first two races that might be affected. The police will be on high alerts and organisers will have to figure out how to deal with the situation.

Three Days of West Flanders organiser Rik Goethals told WTV: "We must now wait and see what will be decided. Let's hope it's not too bad, but, for example, we might have to deploy double the number of police. The financial impact would be huge."

The hills of West Flanders host stretches of many of the Spring Classics, and are used by the Handzame Classic and Gent-Wevelgem. Normally the Ypres police send about 60 officers, but that number could be doubled by bringing in extra staff from other districts.

Sunday March 15 sees the 2.1-rated Kattenkoers from Deinze to Ypres. By then, the threat may have dropped from level three, but the organisers are taking precautions and recruiting extra marshals.