The Truckers and Drivers Union said on Thursday that strikes had expanded to over 141 cities, vowing to continue until demands are met.

“This unity and solidarity is the result of your determination,” the union wrote in a statement. “Thanks to all the drivers, small freight operators, teachers, retirees, workers and free citizens who joined us. Our path is clear and we will persist.”

Truck drivers first walked off the job on May 22 to protest surging fuel costs, a lack of insurance coverage, and stagnant freight rates. Despite efforts by authorities to suppress the action—including arrests and interrogations in multiple provinces—footage from cities such as Bandar Abbas and Marivan shows major highways emptied of heavy vehicles.