Updated at 8 a.m.

DENHAM SPRINGS — Two oil tanks that have been on fire for more than 8 hours will have to burn for another two to three hours before firefighters can smothered the blaze with foam, authorities said Friday morning.

An explosion at a ruptured oil tank on Linder Road, between Denham Springs and Watson, caused the fire which spread to a second tank that cracked and expanded the blaze. The two oil tanks hold about 2,300 barrels of crude oil, said Mark Harrell, director of Livingston Parish Office of Emergency Preparedness and Homeland Security.

No one was injured, Harrell said.

Harrell said about 30 homes within a 1 mile radius of the tanks were evacuated.

Harrell said people in nearby residences were not in any immediate danger from chemicals resulting from the fire. He estimated that the flames were as high as 30 to 35 feet Thursday night.

Harrell and Livingston Fire District No. 5 firefighter Capt. Charlie Weaver both said residents should be able to go back to their homes later Friday afternoon or Friday night.

Harrell said Ferrara Fire and Apparatus, which is based in Holden, was bringing in three pallets of fire suppressive foam. Each pallet has 27 five-gallon buckets, he said.

The company that owns the tanks is Denbury Offshore Resources, Weaver said. Denbury has a private crew that is leading the firefight with assistance and backup from District 5, Weaver said.

Harrell said the oil was contained in a 50-foot berm, which is standard procedure for this type of incident.

Harrell said Thursday the fire was encompassing about a 200 square foot radius in the vicinty of Linder Road and Arnold Road just northeast of Denham Springs.

Harrell said authorities do not know what caused the explosion and fire. The company that owns the active well and the nearby tanks, Denbury Offshore Resources, followed all the rules for containing the oil leak and the resulting fire, Harrell said.