Local people protested outside the 3GSM trade show in Barcelona last night over the increasing volume of wireless signals which they claim to be harmful to health.

As delegates to the conference left last night, a small group of protestors, mainly elderly, held up homemade banners and placards protesting against the increasing use of wireless data and mobile phones.

"Think of health, not business," the leader shouted via a megaphone. "No to mobiles, yes to health."

The group numbered fewer than 50 and was closely monitored by Spanish police, who formed a line to keep them away from delegates.