Two children have died and another two are seriously injured after a shed caught alight southwest of Melbourne.

Emergency services were called to the blaze at the Corio property, near Geelong, just after 10.30am on Sunday.

Two children died at the scene while the other two were flown to hospital, both in a serious condition.

All four children are yet to be formally identified.

The exact cause of the fire is yet to be determined but it’s not being treated as suspicious.

Police will prepare a report for the coroner.

-AAP