The Minneapolis Park and Recreation Board filed an unfair labor practice charge Thursday against striking park workers over disrupted operations at Sea Salt Eatery and the Bread and Pickle restaurant.

Picketers on Wednesday blocked delivery trucks from accessing the restaurants, which are housed in Park Board-owned buildings at Minnehaha Regional Park and Lake Harriet.

The Park Board charges that the union's actions were "unfair," an allegation that was dismissed by Liz Xiong, a spokesperson for Laborers' International Union of North America (LIUNA) Local 363.

"The charge is meritless," Xiong said. "LIUNA Local 363′s picket is lawful. We'll follow the process to address this. The Park Board would better serve its workers and the community if it focused on working out a fair contract and ending the strike."

Outside Sea Salt Eatery in Minnehaha Park, picketers convinced one truck driver not to make their deliveries, the Park Board said in a statement. A second driver was "intimidated" and made Sea Salt staffers unload the delivery truck a block away with the help of Minneapolis Park Police.

Picketers "similarly harassed and blocked essential truck deliveries" the same day at Bread and Pickle on W. Lake Harriet Parkway, according to the statement.

Disruptions were also reported Thursday outside the Park Board's Southside Operations Center, 3800 Bryant Av. S. For 90 minutes, Park Board officials said, picketers blocked employees from arriving and departing the facility in work vehicles.

Members of LIUNA have been on strike since July 4, demanding an increase in wages and improved benefits and safety precautions. Negotiations between the two sides again broke down Tuesday night. Minneapolis Mayor Jacob Frey has offered to step in as convener, but his offer was declined by Park Board President Meg Forney.

Wednesday's picket was the latest disruption at Sea Salt, which in recent days has been hampered by a power outage and a fire, forcing it to operate with a limited menu. The full menu was restored Wednesday evening.

Star Tribune staff writer Susan Du contributed to this report.