Police launch an investigation after a report of a sexual assault involving a lone woman on a train in south London, according to a report. The incident is said to have taken place on Monday, 29 June, at around 5.50pm. The train route described runs between London Victoria station and Tulse Hill. A search is reportedly underway following the allegation, but details about any suspect, injuries, or arrests are not provided in the available reporting. The report characterises the victim as a lone woman and describes the offence as a sexual assault, while not specifying the nature of the assault or whether there were witnesses. The train and time information are presented as the key details so far, with the investigation focused on establishing what happened and identifying those responsible.