On Friday morning, three Russian MiG-31 fighter jets unlawfully crossed into Estonian airspace near the island of Vaindloo.
This was reported by the Estonian Defence Forces, citing Postimees.
The aircraft remained in the Estonian airspace for approximately 12 minutes.
The fighters did not submit flight plans, and their transponders were turned off. Additionally, there was no two-way radio communication with Estonian air traffic controllers at the time of the violation.
The Estonian Ministry of Foreign Affairs summoned the chargé d'affaires of the Russian embassy in Estonia and handed him a note of protest.
This marks the fourth violation of Estonian airspace by Russian military aircraft this year.
On September 7, a Russian Mi-8 helicopter also breached Estonian airspace.