Idled trucks in northern Iran's Rasht city display a sign urging truck drivers to keep up their struggle for better working conditions, in this photo sent to VOA Persian by an audience member and dated May 24, 2018. The license plates have been mostl
Idled trucks in northern Iran's Rasht city display a sign urging truck drivers to keep up their struggle for better working conditions, in this photo sent to VOA Persian by an audience member and dated May 24, 2018. The license plates have been mostl

Iranian truck drivers have extended a strike into a third day in at least four cities around the country, causing gasoline shortages in Tehran and elsewhere.

Video clips, sent by Iranians to VOA Persian and identified as filmed Thursday, show idled trucks in the southern port of Ganaveh and the western city of Arak.

WATCH: Truck drivers' strike idles trucks in Bandar Ganaveh, Iran, May 24, 2018

WATCH: More trucks idled by striking drivers in Arak, Iran, May 24, 2018

Another clip shows a near-empty gas station in eastern Tehran, near the city's Niroo Havayi (Air Force) garrison.

WATCH: Eastern Tehran gas station almost deserted as regular gasoline supplies dry up, May 24, 2018

In the clip, the man holding the camera says it is Thursday at around 7 a.m., when normally there would be a line for drivers waiting for regular gasoline. But, the man says, the gas station told customers that it had not received its regular gasoline supply, leaving the more expensive premium gas as the only option. Rather than pay extra, drivers pass through the gas station and leave, the man says.

A fourth clip shows a long line of cars waiting for gasoline in the city of Isfahan, suggesting that gas shortages were continuing despite state media reports that the situation returned to normal Wednesday.

WATCH: Drivers face long line for gasoline in Isfahan, Iran, May 24, 2018

Iranian state media have reported that gasoline truck drivers were among those who joined the truckers' strike that began Tuesday in at least seven provinces of Iran. Reports said the strike caused shortages at gas stations in Isfahan and the southern city of Shiraz on Wednesday morning, before authorities intervened to persuade drivers to resume gas station deliveries by the end of the day.

Iranian truckers began the strike Tuesday in the provinces of Fars, Hormozgan, Isfahan, Kerman, Khorasan Razavi, Lorestan and Qazvin, according to earlier images and messages sent to VOA Persian. In the images, the striking truckers displayed signs complaining of stagnant wages as they face rising costs for insurance, road tolls, commissions, repairs and spare parts.

In an interview published Thursday by Iran's state-run ILNA news agency, a Road Maintenance and Transportation Organization official said a proposed increase to truckers' cargo payments is progressing.

Dariush Amani is quoted as saying cargo fees paid to Iranian truckers will rise by an average of 15 percent nationwide beginning Saturday. He said the increase may be as low as 10 percent in some places and as high as 20 percent in others. Iran's Road Maintenance and Transportation Organization is a branch of the ministry of roads and urban development, with the authority to regulate cargo fees.

Iran's U.S.-based crown prince Reza Pahlavi posted a Thursday tweet praising the truckers' strike.

Pahlavi said the strike has opened what he called a "new chapter in the non-violent struggle for justice in Iran."

Iran's Islamist rulers long have worried that gasoline shortages could trigger social unrest.

This report was produced in collaboration with VOA's Persian service.