ROSEVILLE, Calif. -- Fire crews battled a multi-alarm blaze at a Roseville department store Tuesday.

The fire at the Ross store at Roseville Square was first reported just before 11 a.m. and quickly went to multiple alarms.

Units from the Roseville, Sacramento Metro, South Placer and Rocklin fire departments responded, as well as crews from other surrounding communities.

"We have at least 10 fire engines and two ladder trucks on scene and we have no reported injuries at this point," Roseville Fire Department spokesman Dennis Mathisen said.

Authorities said the blaze began in the rear of the store and was contained to the Ross store.

Tim Ballard, who said he was working on the lights inside the store when the fire broke out, told KCRA 3 that he suspected sparks from welders working behind the store may have ignited cardboard in the back of the building.

Authorities later confirmed that welders were working behind the store when the fire started and that they likely sparked the blaze. The welders were from the company Handyman Matters, which contracts with Ross.

Fire officials also said that the store was built before sprinklers were required and did not have a fire sprinkler system. Authorities credited a fire wall between the Ross store and the rest of the shopping center with keeping the fire from spreading to other businesses.

The Roseville Police Department shut down Harding Boulevard between Douglas Boulevard and Lead Hill Road and the California Highway Patrol shut down the westbound Douglas Boulevard exit from Interstate 80 to keep traffic out of the area.