New Delhi, March 6 -- Azerbaijan on Thursday accused Iran of a drone attack on its territory that injured four civilians, and it vowed to retaliate as the war in the Middle East reached into another country.

Azerbaijan's Foreign Ministry said in a statement that Iranian drones attacked its exclave of Nakhchivan and damaged an airport building.

President Ilham Aliyev accused Iran of carrying out "a groundless act of terror and aggression," and said his military has been told to prepare and implement retaliatory measures. The Caspian Sea nation halted truck traffic across the nearly 700-kilometer (over 400-mile) border with Iran.

Iran's general staff of the armed forces denied it had launched a drone toward Azerbaijan's territory. Iran h...