Iran's military said on Sunday it had shot down a US reconnaissance drone aircraft in eastern Iran, a military source told state television.
"Iran's military has downed an intruding RQ-170 American drone in eastern Iran," Iran's Arabic-language Al Alam state television network quoted the unnamed source as saying.
"The spy drone, which has been downed with little damage, was seized by the Iranian armed forces."
Iran shot down the drone at a time when it is trying to contain foreign reaction to the storming of the British embassy in Tehran on Tuesday, shortly after London announced that it would impose sanctions on Iran's central bank in connection with Iran's controversial nuclear enrichment programme.
Britain evacuated its diplomatic staff from Iran and expelled Iranian diplomats in London in retaliation, and several other EU members recalled their ambassadors from Tehran.
The attack dragged Iran's relations with Europe to a long-time low.
Washington and EU countries have been discussing measures to restrict Iran's oil exports since the United Nations nuclear watchdog issued a report in November with what it said was evidence that Tehran had worked on designing an atom bomb.
Iran says its nuclear programme is entirely peaceful.