Orange County and Inland Empire-Orange County line trains will only operate as far south as the Laguna Niguel/Mission Viejo Station until further notice, according to Metrolink.
There will be no alternate transportation to or from either San Clemente or Oceanside.
There is no timeline as to when the tracks will reopen or when rail service will resume.
Metrolink track and engineering teams are working collaboratively with the Orange County Transportation Authority and San Clemente officials to ensure the right of way is safe, Metrolink announced.
The tracks are also used for Amtrak's Pacific Surfliner service which has also been suspended, Amtrak announced. Surfliner passengers are being offered bus connections between Irvine and Oceanside for alternative travel during the closure.
The damage caused by the landslide was reported at 4:26 p.m. Wednesday. The affected area is located approximately one-half mile north of Metrolink's San Clemente Pier Station, according to Metrolink.