LONDON — A passenger train derailed near London on Friday, British Transport Police said, the second derailment in two days after two people were seriously injured when another train came off the tracks on Thursday. Police said officers, paramedics and firefighters were at the scene near Wickford train station in Essex, about 30 miles east of London (48 kilometres), after receiving reports that the rear carriages of a train derailed. The carriages were in an “upright position,” police said, and no injuries were reported. National Rail said officials were working to understand what happened, and major disruptions to train services were expected through Friday afternoon. The incident came less than 24 hours after a train from London to Eastbourne went off the tracks outside the southern English town of Lewes. Three carriages overturned, seriously injuring two people and causing minor injuries for 18 others. All passengers were evacuated within about three hours, the transport police said. The cause of the derailment is under investigation.