By Christina Amann BERLIN, June 10 (Reuters) - Protesters sitting on the road and shouting slogans such as "Free Palestine" blocked roads leading to Berlin's ILA air show on Wednesday, forcing many delegates to walk to the industry showcase where Chancellor Friedrich Merz was due to attend. A Reuters witness said dozens of police were at the scene, with a couple of them seen carrying a protester away. Buses could not reach the venue, and hundreds of visitors were walking to the show, some of them complaining about having to do so.