European cities fortify streets after vehicle attacks

Spain has set about deploying more police, installing bollards and stepping up security around stations and tourist landmarks in the wake of the twin terror attacks which killed 15 people.

"We're looking at introducing (street) obstacles that could be mobile," Joaquin Forn, who is in charge of home affairs in Catalonia, told a news conference on Wednesday.

Catalan authorities may also install some permanent barriers and turn some streets into pedestrian-only thoroughfares, Forn added, and police presence will increase by 10-20 percent.

Spain isn't the only country stepping up its defences in wake of the attacks. With trucks and cars being used as weapons to kill nearly 130 people in France, Germany, Britain and Sweden over the past 13 months, Europe is on alert.

German police this week placed concrete barriers in front of Cologne's world famous gothic cathedral on Wednesday after reports that Islamist militants had sought to target Barcelona's La Sagrada Familia church.

Despite being spared a terror attack, officials Italy have met to discuss security, with authorities in Milan installing concrete barriers on streets leading to the city's Gothic-style main cathedral and the adjacent Galleria Vittorio Emanuele II, a shopping centre popular with tourists.

City officials said that local markets and San Siro Stadium, the soccer venue shared by AC Milan and Inter Milan, would be patrolled more closely.

After two vehicle-ramming attacks in London, on Westminster Bridge and outside a mosque, police have installed a portable system of barriers – some resembling traditional obstacles, and others using flower pots and sculptures – to prevent vehicles from entering pedestrian-only areas.

Large, solid barriers have been installed on the London and Westminster Bridges, along with temporary installations in the capital in St James's Park and Buckingham Palace.

And concrete barriers have become commonplace in Germany at events and festivals across the country, after a truck assault that killed 15 people last year at a Christmas market in Berlin.