Queensland Police have located two children that went missing from the state yesterday.

Police issued an amber alert after the eight-year-old boy and four-year-old girl were reported missing from Harristown since 11.50am, Sunday, believing they were at significant risk.

The children were travelling with 30-year-old Casey Allwood in a 1999 white Toyota Camry sedan with Queensland registration 759 KMD.

They were located safe and well with the 30-year-old woman around 1.30pm today.

Police had reason to believe they had crossed into NSW, but have not made public where the children were found.

If you have information for police please call Crime Stoppers on 1800 333 000