Piran is the official host town this year.

The event will also be more eco-friendly and sustainable than ever. Organisers are calling on runners to avoid the use of disposable plastic bottles and straws.

The half marathon started in Koper and the full marathon began in Portorož.

Free busses were also laid on to take competitors between the main starting and finishing points.

Up to 20,000 spectators are expected to turn out today, weather permitting, to cheer on the runners.