Multiple witnesses claim to have heard a loud explosion at roughly 8.15pm near the city center.
Officers have warned people to move away from the Repertory Theatre, believed to have been the site of the blast.
The force said its early investigations suggested a “technical fault” occurred in a “staff only area” of the Rep Theatre on Broad Street.
The major roads of Broad Street and Cambridge Street have also been evacuated and cordoned off as emergency services respond to the incident.
However, there are not believed to be any concerns the incident was terror-related – and there are no reported casualties or injuries at this time.
In a statement West Midlands Police said: “All emergency services are currently at Birmingham’s Repertory Theatre, Broad St following reports of an explosion.
“Initial indications are that this was a technical fault in a staff only area. No casualties are reported.
“Everyone has been evacuated and are being kept safe.”
West Midland Fire Service added: “We are currently supporting West Midlands Police at an incident at the Birmingham Repertory Theatre, Broad St, Birmingham.
“Please AVOID the area.”
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The explosion caused concern around the city, with many attempting to reach out on social media to understand the nature of the blast.
Taking to Twitter, one said: “Huge explosion in town, Birmingham, near the canals about 8:15pm.
“Rep Theatre evacuated. Police and ambulances everywhere. Very disturbing.”
More to follow..