A Civic Centre staff member called the Police after reportedly witnessing a man on West Street pin a woman on the ground and beat her violently.

Sergeant Dean Hanrahan from the Criminal Investigation Unit interviewed staff on the Civic Centre lawn following the assault.

Two officers apprehended a man outside Mount Isa Cinema on Rodeo Drive, while two more officers were seen speaking to a woman nearby.

The two individuals were escorted off the scene in separate Police vehicles.

Queensland Ambulance Service was at the scene with two paramedics stationed outside the cinema. 

Mount Isa Police Inspector Chris Hodgman confirmed police attended two crime scenes at West Street.

"It is a domestic violence situation under investigation," he said.