Demonstrations against austerity overshadowed the inauguration of the new European Central Bank (ECB) headquarters this morning, with occasional bouts of violence breaking out in Frankfurt.

While the protests, organised under the 'Blockupy' banner, were largely peaceful, images from the event show a minority clashing with the local authorities – even setting alight some police cars.

ECB president Mario Draghi acknowledged European unity "is being strained" in his remarks at the inauguration