BERLIN (AP) — A major road tunnel in the Swiss Alps has been closed after a fire aboard a German bus that left two people suffering from the effects of smoke inhalation.

Swiss police in Graubuenden canton (state) said the bus caught fire in the San Bernardino tunnel just after 1 p.m. on Friday. They said everyone aboard the bus and other vehicles in the tunnel were able to leave the scene.

The tunnel in southeastern Switzerland was closed and it wasn't immediately clear when it would reopen.

Authorities reported long lines of traffic Friday at the northern entrance to the Gotthard tunnel, one of the few other major routes across the Alps.