Landslides and flooding from heavy rains in Sao Paulo state have killed at least 18 people since Friday, including seven children, public safety officials said on Sunday.

According to Sao Paulo state authorities, nine other people were injured in the rains and five more were missing, while some 500 families were left homeless across the state.

Sao Paulo Governor Joao Doria flew over the flooded areas on Sunday and said he had authorised 15 million reais ($2.79 million) of emergency aid for the affected cities.

The hardest-hit municipalities around greater Sao Paulo included Aruja, Francisco Morato, Embu das Artes and Franco da Rocha.

Since December, heavy rains have triggered deadly floods in northeast Brazil, threatened to delay harvests in the midwest and briefly forced the suspension of mining operations in the state of Minas Gerais.