SUN PRAIRIE - Several people were hospitalised after a gas explosion rocked the city of Sun Prairie in the state of Wisconsin on Tuesday (July 10), reported US media.

Multiple buildings were levelled in the incident, which took place around Main Street, WISC-TV reported, citing police.

Sun Prairie police officer Kevin Konopacki said at least three emergency responders were injured after they responded to reports of a gas leak at 6.21 pm local time in the 100 block of West Main Street in downtown Sun Prairie, reported Wisconsin State Journal.

A five-block radius around the epicentre of the explosion was evacuated, including a nursing home. The Barr House and Glass Nickel Pizza were severely damaged in the incident.

A spokeswoman for WE Energies said a contractor hit a natural gas main in downtown resulting in the explosion.

"They're working in conjunction with the fire department to make things safe," WE Energies spokeswoman Cathy Schulze said.

Witnesses said a boom occurred at about 7.15 pm that shook the city of about 30,000 people.

A large plume of smoke was rising from the downtown area.

Sun Prairie warned residents near the Main Street and Bristol Street intersection not to use electrical devices, use open flames or anything that could create a spark or start a vehicle.

Video posted to social media showed fires blazing with smoke hurtling toward the sky alongside a heavy police presence, reported Fox News.

An employee of WMTV said his "whole house shook" from the explosion.