(CNN) -- About 300 additional firefighters joined a battle Tuesday to contain a growing wildfire in California's Sequoia National Forest.
As of Tuesday afternoon, the fire had spread across roughly 6,000 acres, U.S. Bureau of Land Management spokeswoman Michelle Puckett said. The bureau is working with the U.S. Forest Service and the Kern County Fire Department to fight the blaze.
"The fire is not contained at this time," Puckett said. "Firefighters are aggressively trying to contain this fire with the winds and the weather changes."
She said that higher temperatures Tuesday have helped stoke the flames. A total of 1,000 firefighters were working the blaze.
The fire started about 1:30 p.m. Monday afternoon. Puckett said the cause of the blaze is under investigation, but "we've heard reports that it might be human caused."
Authorities evacuated campers as well as residents in the Riverkern community, where six homes were destroyed.
A firefighter suffered a minor eye injury from a tree branch, but no serious injuries have been reported, Puckett said.
Visitors and residents are warned to keep their car and house windows closed, as there is a lot of smoke in the area, Puckett said.
Some of the evacuated campers were escorted back to retrieve their belongings Tuesday. Authorities have relocated a number of campers to the Lake Isabella area.
Puckett said she did not have an exact count on the number of people evacuated.
The national forest of 1.2 million acres is one of 19 national forests in California. It takes its name from the giant sequoia, the world's largest tree, which grows in more than 30 groves on the forest's lower slopes.
This is a prime time for tourism in the area, with no vacancies at hotels and bed-and-breakfasts, Puckett said.
"Rafting is huge in Kernville and very popular," she said, adding that vacationers should check with their rafting companies to get information on cancellations.
Puckett said wildfires can be sparked by people using off-road vehicles and lawn equipment during midday. She said that using such equipment during early morning and evening hours, when temperatures are lower and humidity is higher, can help minimize the risk of starting a fire.