The employees were travelling by road yesterday when they were detained by a local armed group, said Marek Resich, an ICRC spokesman.
"The ICRC is currently in contact at various levels to secure the safe release of its team," he said.
The aid workers were delivering sheep to local villages when they were stopped by the gunmen, said Raouf Ahmadi, a police spokesman in Herat province. He said the gunmen took both the workers and the sheep, which could indicate that the abduction was part of a robbery as opposed to a militant attack.
But recent attacks have rattled civilian aid workers. On July 24, gunmen opened fire on two Finnish aid workers in the city of Herat, killing them both.
Herat is one of Afghanistan's largest provinces. It borders Iran to the west and has become as center of trade with Iran and central Asia.
