CHATTANOOGA, Tenn. – Two new wildfires began Monday, adding to an outbreak of more than a dozen blazes in eastern Tennessee that included 10 suspected as arson.

As of Monday morning, the fires north of Knoxville had burned 2,300 acres – more than three and half square miles, said Nathan Waters, a state assistant district forester.

Ten were arson related, one was caused by fireworks and two were debris fires that got away, he said.

“We’ve still got all kinds of fire left,” said Robert Rhinehart, assistant district forester in the Chattanooga Forestry Division office.

A fire below Signal Mountain, near Chattanooga about 10 miles from the Georgia line, was still causing firefighters trouble Monday morning, Rhinehart said.

The blaze was bad enough Sunday that crews used a fire-retardant drop for the first time in the region since 1991, he said.

The retardant slowed the spread of the fire, but firefighters were still working along the eastern end of the blaze where authorities worried it could jump a creek and threaten homes.

Warm, dry weather contributed to the fire danger.

Sunday’s high temperature at Chattanooga was a record 88 degrees.

Authorities haven’t discussed details of the fires they believe to be arson.

Firefighters in Campbell County worked to keep flames away from 23 vacation cabins on Sunday.

A 15-man volunteer crew of inmates from Brushy Mountain Correctional Complex was sent for “mop up” duty to help firefighters manning fire lines after only a few hours of sleep, Waters said.

The Highway Patrol also stationed troopers along Interstate 75 to caution drivers to slow down because of smoke produced by one fire that had charred more than 100 acres. Scattered afternoon showers were forecast Tuesday and Wednesday but were expected to have little effect.

More significant rainfall was expected Saturday, said Doug Schneider, a forecaster with the National Weather Service.

The area’s rainfall total since Jan. 1 is 6.28 inches – less than half the 30-year average of 15.34 inches for that time period.