Iran said an unidentified drone crashed near its border with Azerbaijan on Tuesday.
The drone crashed in a village in Parsabad, Ardebil Province, along Iran's northern border, Deputy Governor Behrouz Nedaei said.
"The drone's identity and cause of its crash in the area are being investigated," he said, reporting no damage, AFP wrote.
According to IRNA, the drone "may belong to Azerbaijan or Armenia given the fighting beyond Iran's northern border".
Earlier this month, northwestern Iranian border regions were, on several occasions, hit by stray mortar shells and rockets exchanged between the armies of Armenia and Azerbaijan.
Those incidents prompted stern warnings from senior Iranian officials, with Defense Minister Brigadier General Amir Hatami pledging stronger measures than warnings if such incidents were repeated.
Iran has called on both sides to cease hostilities and offered to facilitate talks.
The two neighbors have for decades been locked in a dispute over Nagorno-Karabakh, an ethnically Armenian area which broke away from Baku in a 1990s war that cost about 30,000 lives.
Baku has never hidden its desire to win back control and no state has ever recognized the independence that was self-declared by Nagorno-Karabakh.
Heavy fighting erupted on September 27 in one of the most combustible frozen conflicts left over from the collapse of the Soviet Union.
More than two weeks of conflict between the Caucasus rivals has left almost 600 dead, including 73 civilians, according to a tally based on partial tolls from both sides.
Armenian and Azerbaijani forces on Tuesday engaged in new fighting over the disputed region despite pleas from world and regional powers for them to observe a cease-fire agreed last week.
The Nagorno-Karabakh separatist authorities accused Azerbaijan of launching an offensive in the south, north and northeast of the region.
Baku claimed that Armenians had launched strikes on the Azerbaijani districts of Goranboy, Terter and Agdam.
The fighting, which repeats a pattern seen over the last days, has made a mockery of the cease-fire agreed between the Armenian and Azerbaijani foreign ministers in the early hours of Saturday in Moscow after a marathon session of talks.
Russian Foreign Minister Sergei Lavrov on Monday acknowledged that the cease-fire was not holding and urged both sides to immediately begin implementing it.
The European Union and Iran have also called on the parties to properly observe the cease-fire.
But concerns remain over the role of Turkey, which has strongly backed Azerbaijan and stands accused, notably by French President Emmanuel Macron, of dispatching pro-Ankara Syrian militants to assist Baku.
According to the Britain-based Syrian Observatory for Human Rights, 1,450 such militants have gone to Azerbaijan including 250 who traveled in the last week alone.
It said that 119 of them have died, with 78 of them already repatriated to Syria with other bodies still in Azerbaijan.