An IP source said that the issue is a fault at Cais do Sodré, in Lisbon.
The same source also said, at around 09:00, that the extent of the damage is being assessed, and there is currently no forecast as to when circulation will resume.
The Cascais Line connects Lisbon to Cascais, in the same district, also passing through the municipality of Oeiras (where the Algés station is located).