Authorities in Pennsylvania discovered more explosives were stolen than originally thought from a work site in Lancaster County over the weekend.

Investigators conducted a full inventory and learned an additional case of dynamite was missing, making the new total 704 pounds of dynamite, WGAL reported on Tuesday. Authorities at first believed the amount to be 640 pounds.

The federal Bureau of Alcohol, Tobacco, Firearms and Explosives is offering a reward of up to $10,000 for information that leads to the recovery.

A contracting company reported the theft Monday, the Lebanon Daily News reported. The missing explosives also include 400 blasting caps, the report said. A blasting cap is used to trigger an explosive device.

The explosives were reportedly left in a locked trailer Friday at the Atlantic Sunrise pipeline worksite in Marietta. Harrisburg's Fox 43reported that the work site security company discovered the heist Monday.

The ATF, Pennsylvania State Police and other agencies are investigating.

“The ATF, along with our law enforcement partners are committed to ensuring that our communities are safe and that those who violate federal explosive laws are held accountable,” Donald Robinson, special agent in charge, said. “We are asking for the public’s help in our effort to apprehend and convict those responsible.”

Fox News' Edmund DeMarche contributed to this report.