Customers and staff at a Big W store in Melbourne's west were evacuated on Tuesday after clothes were set alight in the middle of the store.

Firefighters were called to the Big W store in Central Square shopping centre at Altona Meadows about 6pm.

Embattled Big W chain is facing more upheaval as Woolies is working to turn around its fortunes. Credit:Glenn Hunt

It is understood there were two small fires in separate areas.

"There was smoke in the store," Metropolitan Fire Brigade spokeswoman Heather Stockton said.