Around 40 schoolchildren are awaiting rescue after their bus slid off a road near Crymych in Pembrokeshire.
The pupils, from Ysgol y Preseli, were on their way home after their school closed early due to bad weather.
It happened between Maenclochog and Mynachlogddu. There are no reported injuries.
A spokesperson for Pembrokeshire County Council said: "The pupils are staying onboard while waiting for a relief bus to collect them and continue their journey."
On Monday, 16 children and three adults had a lucky escape when a schoolbus slid off the road and became trapped on an embankment in the village of Llanfach, near Abercarn.