Iranian authorities on Wednesday arrested at least 11 pro-Azerbaijan protesters, according to the Iranian Human Rights Activists News Agency, Anadolu reports.
It said police forces used tear gas to disperse activists who gathered at a park in Ardabil city in solidarity with Azerbaijan in the wake of Armenian attacks.
The police arrested at least 11 activists and wounded three others, it added.
A large number of Azerbaijanis, who constitute a large proportion of the population of the cities of Ardabil, Tabriz and Urmia expressed their support for Azerbaijan.
Border clashes broke out earlier in the day after Armenian forces targeted Azerbaijani civilian settlements and military positions. The number of casualties is not yet known.
Armenia has once again proved that it is the biggest obstacle to peace and stability in the region, the Turkish Foreign Ministry said earlier in a statement, adding Turkey will stand with Azerbaijan by all means.
Baku has the right of self-defense to protect its people and territory, it added.
Relations between the two former Soviet nations have been tense since 1991, when the Armenian military occupied the Upper Karabakh, or Nagorno-Karabakh region, an internationally recognized territory of Azerbaijan.
Four UN Security Council and two UN General Assembly resolutions, as well as many international organizations, demand the withdrawal of the occupying forces.
The OSCE Minsk Group — co-chaired by France, Russia and the US — was formed in 1992 to find a peaceful solution to the conflict, but to no avail.