"Units of (the IRGC) Ground Force have been dispatched to and stationed in the region," their commander Brigadier General Mohammad Pakpour said.
Their mission is "to protect national interests and maintain peace and security".
Pakpour said Iran respects its neighbors’ territorial integrity but that "any shift in border geopolitics is the Islamic Republic of Iran's redline".
The commander visited the border county of Khoda Afarin on Saturday. He said even though some of the projectiles had landed on the Iranian soil during the firefight, “security prevails over [our] borders, and no danger threatens the country.”
The region in Iran's East Azarbaijan Province borders territory in Azerbaijan adjacent to Nagorno-Karabakh.
Khoda Afarin and nearby villages have been hit by stray cross-border mortar fire.
"If there is any repetition of such fire, the Islamic Republic of Iran will not remain indifferent," Foreign Ministry spokesman Saeed Khatibzadeh warned on October 16.
Iran’s Defense Minister Brigadier General Amir Hatami also put the warring sides on notice early this month, saying Tehran would respond beyond only warnings if the security of Iran’s border regions were endangered.
In the first week of the fighting, mortar rounds strayed across the border, with one wounding a six-year-old child.
No more stray fire
Speaking in an interview with the French newspaper Le Figaro, Azerbaijani President Ilham Aliyev reassured Iran that his country had completely “cleaned” the border area.
“There will be no more inconvenience for our brothers across river of Aras in Iran,” he added.
“As far as I know, Iranian leaders also talk to [the] Armenian side. Because the clashes were taking place just by the river Aras, close to the border with Iran, and by accident, some of the weapons crossed the border,” Aliyev said.
“But today we announced that we cleaned completely the Azerbaijani-Iranian border from Armenian occupants. Therefore, no more clashes take place there, and there will be no more inconvenience for our brothers across the river,” he added.
Armenia and Azerbaijan have for decades been locked in a conflict over Nagorno-Karabakh, an ethnically Armenian region of Azerbaijan which broke away from Baku in a 1990s war.
Both sides have defied international calls for a cease-fire since all-out war erupted on September 27.
On Thursday, Azerbaijan said it had taken full control of its border with Iran as Baku pressed ahead with its operations in Nagorno-Karabakh, driving out Armenian forces near the frontier.
Armenia also borders northwest Iran.
AFP and Press TV contributed to this story.