Safety needs to be improved at 26 railways tunnels in Switzerland, according to a new report by the transport ministry. It was commissioned last year following fatal accidents in the Mont Blanc tunnel in France and Tauern in Austria.
The study, released on Monday, found that the vast majority of Switzerland's 689 railway tunnels were safe and allowed for the possibility of a speedy evacuation in the event of fire.
However, it found that longer tunnels of three kilometres or more were less safe. The report said improvements needed to be made in a number of areas, specifically tunnel ventilation, lighting and the clear marking of emergency exits.
Railway operators have been given until the end of September to announce what improvements they intend to make in the light of the report.
Among the 26 tunnels which failed to meet the safety requirements were the important Gotthard, Lötschberg and Vereina tunnels.
According to the report, most Swiss tunnels have not had any major maintenance work done on them for 20 years or more. Despite that, it says rail travel continues to be far safer than road transport.
Between 1990 and 1997, 48 people died in accidents on the Swiss railways, while 743 died on the roads.
swissinfo with agencies