Peel Road in Douglas is currently closed between the Brown Bobby and the junction with Railway Hill and Athol Street as the Isle of Man Fire and Rescue Service deals with a structure fire.
The closure, announced shortly after 4.30pm today (Tuesday), will likely cause significant disruption to rush-hour traffic in the area.
Police are urging the public to avoid the route until further updates are provided.
Further details about the nature of the incident have yet to be released, but emergency services remain on site.
Commuters and residents are advised to seek alternative routes and allow extra time for their journeys.
The Isle of Man Constabulary are expected to issue further information as the situation develops.