A rocket was fired on Sunday on a military base in Kandahar, Afghanistan, while Bulgarian Defence Minister Nikolay Mladenov was visiting his country's troops there.
Four Bulgarian soldiers were injured in the attack, the Defence Ministry in Sofia said late on Sunday.
The rocket exploded just 200 metres from the minister's party, but he was unharmed.
Some 270 Bulgarians are part of the international military force in Kandahar. The country has a total of 500 troops in Afghanistan.
Mladenov is to remain in Afghanistan until Thursday.