Investigators say a forest fire that burned more than 11,000 acres of the New Jersey Pinelands was caused by human activity in an area known for illegal bonfires.

The state Forest Fire Service stopped short of saying whether the blaze was deliberately set or caused accidentally, saying an investigation is ongoing. The fire was declared to be 100 percent contained on Monday, having burned 11,600 acres.

The blaze was spotted Saturday afternoon in the Penn State Forest in Woodland Township. Investigators say it began in a remote section of forest where people have been known to start illegal bonfires.

Smoke from the fire could be seen and smelled all across the state. But no homes or businesses were damaged by the blaze, and no injuries or mandatory evacuations were reported.

State fire warden Greg McLaughlin says that it was a job well-done.

"April is fire season in New Jersey and we need to be vigilant in our messaging to the public to help us to do what we need to do,” he says.

New Jersey DEP Commissioner Catherine McCabe flew over the burned area Monday morning to survey the damage.

“Luckily today I saw absolutely nothing in the way of smoke or fire but I did see the areas of the burn and the backburn areas the fire service ignited to keep the fire under control,” she said.

Fire crews remained on standby at the Coyle Air Strip in case the fire sparked back up.

Fire officials are asking anyone who may have seen people in the area of Spring Hill Road near the woods around 12 p.m. on March 30 to call New Jersey State Police at 609-296-3132.