A tractor-trailer has jackknifed on Interstate 79 in Lawrence County just over the Butler County line, tying up traffic in the southbound lanes.

A hazardous materials response team was been called to deal with about 100 gallons of fuel that leaked from the truck.

The accident occurred about 7:30 a.m. in the southbound lanes of the highway near mile marker 106, just north of the Slippery Rock exit.

State police in Mercer said there were no injuries reported and no other vehicles are believed to be involved.

Traffic on the southbound lanes has been reduced to one lane.