Switzerland’s main north-south route through the Alps is to stay closed for at least another three weeks due to fears of further rockslides.The A2 motorway leading to the Gotthard tunnel was closed last Wednesday morning after a landslip killed two people who were travelling in a car. It re-opened on Friday only to be closed again after more rocks plunged down the mountainside between the villages of Amsteg and Göschenen. “We only learned that the Gotthard will be closed for at least the next three weeks. We will have more information after we have carried out controlled detonations this week,” said Thomas Rohrbach from the Swiss Federal Roads Authority. Geologists say rockfalls could happen at around 50 locations along the carriageway. Boulders of up to 15 tonnes could reach the road. As a result of the closure Swiss railways put on extra trains to cope with the demand over the holiday weekend. But the measure could not prevent long tailbacks developing on alternative routes, like the San Bernardino.