A direct mailing firm with local operations in Logan and Woolwich townships is citing “industrial sabotage” in a decision to cease operations at five facilities nationwide.

Approximately 600 employees of the two local plants operated by DGI Services will lose their jobs between now and Jan. 31 under a letter obtained Thursday by Gloucester County officials.

“We regret to inform you that DGI Services LLC will be forced to close its facilities due to certain unforeseeable business circumstances,” the letter reads.

“In particular, one of our facilities was recently subject to an act of industrial sabotage which resulted in irreparable damage to our ability to continue our operations. The perpetrators of this unlawful entry vandalized certain equipment integral to the operation of our business beyond immediate repair and obtained access to our IT room.”

Michelle Haenggi, human resources director at DGI, did not return calls placed by both the Times and Lisa Morina, director of the Gloucester County Office of Economic Development.

An email sent Thursday to the Times by an individual purporting to be a DGI employee said the sabotage occurred at one of the Gloucester County operations approximately three weeks ago. The incident is under investigation by the Philadelphia office of the FBI, according to local law enforcement officials.

DGI has facilities on Berkeley Drive in Woolwich Township and Center Square Road in Logan Township. Morina said DGI and its predecessors have been a part of the county workforce for approximately 15 years. The current owners have been in place since January, according to Morina.

The letter DGI sent employees citing the sabotage, “as well as our recent loss of clients and unsuccessful efforts to obtain business,” side-steps provisions of the state Worker Adjustment and Retraining Act, which requires 60 days’ written notification before a facility of at least 100 workers can issue mass layoffs.

Industrial sabotage is one of the exceptions to provisions of the WARN act.

In addition to the two Gloucester County facilities, DGI is shuttering operations at two locations in Cerritos, Calif., and one in Fort Worth, Texas.

On Tuesday, IWCO Direct of Chanhassen, Minn., announced it had purchased some of the assets of DGI Services.

“IWCO Direct will transition the acquired assets to its existing locations in California, Minnesota and Pennsylvania,” the firm’s statement reads.

“We acquired the assets,” said Debora Haskel, IWCO’s marketing director. “We did not acquire the buildings or the business.”

Asked to elaborate on “assets,” she replied “we acquired equipment.”

IWCO has a direct marketing facility in Warminster, Pa.

The letter from the company says DGI “will not be providing payments to our employees as provided by the NJ WARN Act.”

Morina said her office had forwarded information regarding the DGI shutdown of its Gloucester County operations to the state Department of Labor “so they could engage their rapid response team.”

That team will meet with affected employees to explain “options,” said Morina.

The county will also make available its “one-stop” services to explain training options, she added.

“We had already been planning a career fair,” Morina said. “We are bumping it up to an earlier date so we can accommodate these people.”

The economic development director said several graphic designers and salespeople have been employees of DGI for as long as it has existed locally.