Iran warned on Wednesday it would shoot down any US spy craft in its skies as a powerful earthworks blast triggered fears of an attack and underscored the high state of tension in Tehran's stand-off with the West over its nuclear activities. Intelligence Minister Ali Younessi confirmed the presence of "American spying instruments" in the skies over Iran and warned that they would be targeted by the military.

"We have the means to hit them and if they get near, our anti-aircraft defence systems will attend to it," said Younessi. "Americans have been conducting spying activities in the Iranian sky for a long time."

Copyright Agence France-Presse, 2005