Security stepped up at tennis championships after activists from 15M group are found trying to smuggle in paint and banners

This article is more than 9 years old

This article is more than 9 years old

Security has been stepped up at Wimbledon, after a group of Spanish activists tried to smuggle banners and tins of paint inside the tennis championship.

Police said they believed the 14 members of 15M London, which is linked to the mass protests in Spain, planned to target the match between world number one Rafael Nadal and Gilles Muller on court one.

The tournament went into lockdown after the protesters, all Spanish and wearing yellow T-shirts, were stopped in the queue, with a Metropolitan Police helicopter hovering overhead. Thousands of fans were delayed as the gates were closed for an extra 45 minutes.

Ian Ritchie, chief executive of the All England Lawn and Tennis Club, said he did not know whether the championships would be targeted again but security would be increased.

He said: "For all we know, we have to be prepared for people coming back in on Monday. We have to be prepared for every eventuality."

Ritchie said personal security for Nadal and other Spanish players had not been altered.

A police spokesman said: "At approximately 10.30am today a number of people were stopped in the queue at the tennis for Wimbledon and items were also found near to this group, believed to be for use in a demonstration or publicity stunt.

"A number of individuals are not being allowed access to the tennis following the searches. No arrests were made."

The planned protest caused no alteration to the playing schedule.

15M London put a message on its website saying: "Important: don't go to Wimbledon – mission aborted." The activists describe themselves as "a movement of outraged citizens" opposed to corrupt politicians and greedy bankers.

Thousands have protested in Spain under the 15M umbrella, amid anger about high unemployment and the stagnant economy.