Officials are concerned about hot and humid conditions as firefighters work to completely extinguish a forest fire in southern New Jersey.

An Environmental Protection Department spokesman says the 225-acre blaze is 90 percent contained and will likely be completely contained by the end of the day. But he says it will take several days to mop up.

Forecasters expect high temperatures to remain in the 90s and approach 100 on Saturday. About 40 firefighters are working to control the blaze.

The fire was spotted Thursday afternoon in Wharton State Forest along the border of Camden and Atlantic counties. Flames are not threatening any structures, and no injuries have been reported.

The cause is under investigation.

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