Locals watch on in horror as massive blaze rips through a Mitre 10 on the Eyre Peninsula

An urgent watch and act alert has been issued to locals in a South Australian suburb after a hardware store went up in flames. 

Tumby Bay residents have been warned to remain indoors after a fire broke out at a Mitre 10 on the Eyre Peninsula, 240km northwest of Adelaide, on Saturday afternoon. 

Fire crews were called to the Spencer Street store at about 3.20pm where they continue to fight the blaze.  

Stunned shoppers were seen standing by in shock as the large flames poured from the roof of the building. 

Locals watched on in horror as the Tumby Bay hardware store went up in flames on Saturday

South Australian Country Fire Service (CFS) issued an alert for a fire at a commercial premises on Spencer Street at 3.23pm. 

Daily Mail Australia understands emergency services will remain at the scene for some time. 

Residents within the warning area, running east-west from Trezise Street and Tumby Terrace and north-south between North Terrace and Park Terrace have ben advised to immediately move indoors. 

The Spencer Street hardware store has served the Tumby Bay community since it opened in 2006. 

For updates, check the CFS website at cfs.sa.gov.au or phone the Information Hotline on 1800 362 361.

More to come.