The strike by a Montgomery County trash hauling contractor, now in its third day, took a rough turn this morning as a picketing worker was clipped by a truck leaving Potomac Disposal in Gaithersburg.

Video taken by WJLA shows an unidentified worker taken from the site by ambulance with unspecified injuries. WJLA also reported that the driver was assaulted by strikers who attempted to remove him from the truck.

The 57 workers, members of the Laborers International Union of North America Local 657, struck Monday. They charged that the company was using threats of immigration enforcement action to gain leverage in stalled contract talks.

A woman answering the phone at Potomac Disposal said president Lee Levine would only speak in person, not on the phone.

Nicole Duarte, a union spokesperson, said workers had offered to return Wednesday, saying that they’d made their displeasure with the company clear. But the gates were locked when they arrived at 6 a.m., Duarte said.

After the lockout was reported, Duarte said, a Potomac Disposal representative contacted the union. “Discussions are under way for a rapid return to work,” she said in an e-mail.

The incident occurred before 7 a.m. In a phone interview, Anibel Rivas, one of the picketing workers, said it was not clear whether the worker was hit by the truck intentionally. But he said the driver used excessive speed in leaving the Potomac Disposal site.

“He came out very, very reckless and in a careless manner,” Rivas said. “He gunned the truck really quick and clipped the guy on the leg with the rear side [of the truck]. There was no need for that.”

County officials said the strike may delay, but not cut off, scheduled pickup in some neighborhoods.