Concrete blocks around Dom of Cologne

At the world-famous Cologne Cathedral, concrete barriers were placed by the German police.

'We took this decision as soon as possible after the recent attacks in Spain,' said a police spokesman. 'It is our job to protect sensitive points and the cathedral is a symbol of Cologne, known all over the world. ''

Spanish media reported that the terrorist cell that commenced attacks in Barcelona and Cambrils initially planned a larger attack on the art nouveau monument of architect Antoni Gaudi, the Sagrada Familia.

Also read: 'Sagradia Familia was target terrorists'