KABUL, Afghanistan — A fuel tanker exploded Saturday afternoon at a crowded border post in western Afghanistan, setting off an enormous fire that spread to more than 100 other tankers as intense flames slowed the response of firefighters and rescue vehicles, Afghan officials reported.
The officials said they had not determined what caused the first tanker to explode at the Islam-Qala customs post on the border with Iran shortly after noon. They expressed alarm Saturday evening that the fire was rapidly spreading at the congested customs complex and could engulf hundreds more tankers lined up at the border.
Officials in Herat said they could not confirm Afghan and Iranian media reports that up to 500 tankers had already burned and that the blaze had spread to the Iranian customs post on the other side of the border.
At least 17 people were injured, with the number of casualties expected to rise, said Mohammad Rafiq Sherzay, the provincial public health spokesman.
Ahmad Tariq Saleh said his company, Hnif Merwan, had lost 21 tankers to the fire.
The tankers import fuel and natural gas from Iran. The United States has granted Afghanistan an exemption to sanctions imposed on Iran to import fuel, though U.S.-backed Afghan security forces are prohibited from using it.
Iran is Afghanistan’s largest trade partner, and the crossing is crucial to the economy of Herat Province and western Afghanistan. A long-term disruption of the crossing could bring hardships to the region.
The Taliban operates so-called shadow governments in much of the countryside outside the city of Herat, while the American-back government controls Herat and other population centers. The militants often set up checkpoints on roadways, imposing taxes on goods and vehicles.
Because of the fire, the electricity supply from neighboring Iran was disconnected as a precaution, leaving the city of Herat without power as night fell, said Jailani Farhad, a spokesman for Herat’s governor. The province’s capital, the city of Herat, is about 75 miles east of the border crossing, located on a major commercial transit route between Afghanistan and Iran.
“All of our forces and our firefighting department are trying to control the fire,” Mr. Farhad said.
Iran was sending firefighters to assist Herat’s fire department, the country’s state-run IRNA news agency reported late Saturday, quoting the director-general of crisis management in Khorasan Razavi Province in northeastern Iran.
David Zucchino reported from Kabul and Asad Timory from Herat.