Two tourist buses collide in Barcelona, 51 injured

Two buses packed with tourists collided on a busy street in Spain's second city Barcelona on Monday, injuring at least 51 people, four of them critically including a minor, officials said.

One bus was parked and picking up passengers on Avinguda Diagonal, one of Barcelona's widest and most significant avenues, when the other smashed into it from behind, the deputy mayor said at the scene of the accident.

One bus was carrying a group who arrived on a cruise ship and were visiting Barcelona's iconic Sagrada Familia basilica while the other was transporting a group of Italian students staying in a nearby town. The cause of the accident is under investigation.