10:45 am (local time): The "Lobby Busters" demo is attacked by riot cops near the Sagrada Familia. The incident was provoked by the arrival of Critical Mass cyclists - the demo (numbering about 1500 people) then began to trickle onto the road, blocking the traffic. Without any provocation, the police began to beat demonstrators with batons. The crowd was baton-charged three times before the cops finally backed off.

2 pm: A large crowd has gathered outside the Liceu metro station for another demonstration. There are probably about 2,000 activists, including a couple of hundred Black Block. It is obvious that a confrontation is going to occur with the riot police, who have deployed officers with batons and guns that fire rubber bullets.

2.25 pm: Something has kicked off at the front of the crowd. The cops repeatedly baton-charge the crowd in order to disperse us. Masked activists are running onto the back streets. There is some minor property damage.

3 pm: The confrontation continues. Many tourists and local people have been beaten up by the cops. Someone must have been badly injured, because there are ambulances trying to get into the crowd. Something is on fire - I discover that some recycling bins have been set alight outside the Meridien Hotel. However, the clashes are gradually becoming more sporadic. Most people I speak to have been beaten, though injuries (including mine) are fairly minor.

4 pm: The cops have left and the crowd has mostly dispersed. However, the trouble is probably not over yet. Another event is due to start in the city centre in less than two hours´ time.