At least 100 oil and gas tankers have been destroyed by fire in a “catastrophe” at Afghanistan’s biggest trade crossing with Iran, causing millions of dollars of losses, officials said Sunday.

The huge blaze, which broke out Saturday afternoon at Islam Qala port 120 kilometers (75 miles) from the western city of Herat, has been contained and an investigation launched into its cause.

“We were told that 100 or 200 tankers have been destroyed, but this number could be higher,” Jailani Farhad, spokesman for the governor of Herat province, said after visiting the scene.

During the blaze looters descended on the site, stealing goods that were being imported and exported across the border, Younus Qazi Zada, the head of the Herat Chamber of Commerce said.

“The catastrophe was much bigger than imagined,” he said, adding: “Unfortunately, irresponsible people have looted a large number of goods.”

Qazi Zada said initial estimates were of “millions of dollars of losses”.