The landslip damaged a railway cutting on Thursday afternoon, Network Rail said, and engineering teams put a “short-term solution” in place to allow trains to continue running.
But the retaining wall collapsed further on Saturday afternoon, which caused concerns about earthworks above.
Network Rail said teams were working to re-open the railway as soon as possible, with services expected to resume in the coming days.
West Midlands Railway said disruption may also include Birmingham Snow Hill line services terminating at Worcester Shrub Hill instead of Foregate Street, adding that rail replacement buses would run between Worcester, Droitwich Spa and Bromsgrove.