- The tourists are from the United States, Britain and Germany
- The convoy hit was accompanied by Afghan Security Force vehicles
Jilani Farhad, a spokesman for Herat's governor, said the tourists were from the United States, Britain and Germany.
The injured were among a party of 11 tourists riding in two vans when the rocket struck. They were traveling through Herat's Chest-e-Sharif district, district chief Farhad Khademi told CNN. The convoy was accompanied by Afghan Security Force vehicles, he added.
"We are providing assistance to British nationals involved in the attack in Herat and are in close contact with the local authorities," Britain's foreign office said in a statement.
The group was around 25 km (16 miles) from the province's administrative center when the rocket struck around 11 a.m. local time (2:30 a.m. ET).
The tourists began their journey in central Bamyan province and traveled through Ghor province, before entering Herat.
Many countries, including the US and UK, have longstanding travel advisories warning against all but essential travel to Afghanistan due to the security situation throughout the country.
In 2014, two foreign aid workers with the International Assistance Mission were killed
in the city of Herat.