It was originally thought that there had been six, rather than three, explosions on the Underground network. The bus bombing brought the reported total to seven; this was clarified later in the day. The erroneous reporting can be attributed to the fact that the blasts occurred on trains that were between stations, causing wounded passengers to emerge from both stations, giving the impression that there was an incident at each. Police also revised the timings of the tube blasts: initial reports had indicated that they occurred during a period of almost half an hour. This was due to initial confusion at London Underground (LU), where the explosions were originally believed to have been caused by power surges. An early report, made in the minutes after the explosions, involved a person under a train, while another described a derailment (both of which did occur, but only as a result of the explosions). A code amber alert was declared by LU at 09:19, and LU began to cease the network's operations, ordering trains to continue only to the next station and suspending all services.