Ten buses have been "torched" in a deliberate fire at a bus depot.
Six double-decker and four single-decker buses were engulfed in flames when firefighters arrived at Abus station in Kingsland Road, Bristol, at 01:45 GMT.
Avon Fire and Rescue said the fire is thought to have been started deliberately. An inspection will be carried out this morning.
Bus services have been affected but are still running in the city.
General manager Tim Loughlin said: "It has had a severe impact but our services are still running.
"Customers should know that many of the buses will be single decker so this could affect services but we are hoping to source more vehicles.
"At peak times, customers may want to seek alternative services."
Avon and Somerset Police has been informed.