ELLENSBURG, Wash. -

A new wildfire has burned across about 4,000 acres, or six square miles, of sagebrush south of Ellensburg in central Washington, temporarily closing a nearby section of interstate highway.

The state Transportation Department said a section of eastbound Interstate 82 was closed for about three hours Thursday night due to the smoky fire in the Manastash Ridge area. The agency says the highway section reopened when the fire was no longer close to the roadway.

Jim Duck at the Central Washington Interagency Communications Center said five helicopters fought the fire with help from several bulldozers and several dozen firefighters.  He said no homes are threatened.

State Natural Resources Department spokeswoman Debbie Robinson tells the Daily Record of Ellensburg that the fire burned around cell towers and TV antennas on the ridge summit without damaging them.

By late Thursday night the fire was considered 5 percent contained. Crews planned to work into the night. The blaze was reported Thursday afternoon and the cause is under investigation.