An emergency alert has been issued for a fire at Lake Macquarie, near Gateshead.

The Rural Fire Service (RFS) says the fire at Oakdale Road has jumped the Fernleigh track.

It has burnt seven hectares of scrub, with 11 trucks and 40 firefighters at the scene, an RFS spokesman said.

He said there were helicopters working at the scene to slow its process.

At 1430 (AEDT) there were 69 bushfires burning across the state, with 29 uncontained.

Around 3000 firefighters are battling the blazes, almost 1000 of whom were reinforcements from interstate.

It is the third fire to reach emergency warning level on Wednesday.

Residents in the suburbs of Redhead and Dudley were advised to seek shelter as the blaze approaches.

Parents are being urged not to pick their children up from Redhead School due to the fire risk on the roads.

The children were safe and well in the school hall, the RFS said.