Iran has confirmed that its forces have shot down a drone and said it belonged to a foreign country, according to state news agency IRNA.
Iran's air defence force hit the "unknown" drone early on Friday morning at the port city of Mahshahr in the country's southwest, IRNA reported.
The report did not state whether the drone was a military or commercially available device.
"The downed drone definitely belonged to a foreign country. Its wreckage has been recovered and is being investigated," the governor of Iran's southern Khuzestan province, Gholamreza Shariati, said, as quoted by IRNA.
Shariati said the drone violated Iran's airspace.
Earlier, semi-official Tasnim news agency reported that the unmanned aircraft was downed over Iranian territory with a domestically manufactured Mersad surface-to-air missile.
Iran's Arabic TV news channel Al-Alam said "residents of Imam Khomeini port city heard the sound of a missile being fired on Friday morning".
Not a US drone
The United States Central Command released a statement later on Friday saying that the downed drone was not one of theirs, and that all military drones were accounted for.
"Alleged reports of a US drone being shot down are incorrect. If a UAS had gone down in the CENTCOM AOR it was not a DoD asset," US Central Command said in a post on Twitter.
In June, Iran shot down an unmanned US surveillance drone, which the elite Islamic Revolutionary Guard Corps (IRGC) said was flying over southern Iran - a move that brought the region to the brink of war.
Washington said the US drone had been shot down by Iran in international airspace over the Strait of Hormuz in the Gulf.
Relations between Iran and the US have worsened since last year when President Donald Trump pulled out of Tehran's 2015 nuclear deal with world powers and reimposed sanctions on the country.