A van has struck pedestrians on London Bridge in central London leaving a number of casualties, including fatalities. Police have declared a "terrorist incident" there and at nearby Borough Market amid reports of stabbings. What happened? Armed police and ambulances were called to reports of a white van hitting several people on London Bridge 22:08 BST on Saturday. The area and nearby railway stations were closed. Witness reports said the van mounted the pavement of the bridge. BBC reporter Holly Jones, who was on the bridge at the time, said: "A white van driver came speeding - probably about 50mph - veered off the road into the crowds of people who were walking along the pavement. "He swerved right round me and then hit about five or six people." Police have said there has been "more than…