Finland summoned Russia's ambassador on Monday after two Russian military aircraft allegedly violated Finnish airspace near the southern coast last week.

The incident has ramped up rising tensions as Helsinki deepens its NATO integration and bolsters defenses against potential threats along its shared border with Russia.

What do we know about Finland's claim?

The suspected breach was off the coast of Porvoo, some 50 kilometers (30 miles) east of Helsinki, and is under investigation by Finnish authorities.

The country's defense ministry first reported the incident on Friday.

"The foreign ministry of Finland has today summoned the ambassador of Russia and requested an explanation regarding the suspected violation of airspace," the ministry said in a post on X.

"The ambassador was told that Finland takes the suspected territorial violation seriously," the ministry said in a statement to the Reuters news agency. It added that the ambassador had indicated he would pass on the message.

Why is Finland concerned?

Finland, which joined NATO in 2023 after Russia's full-scale invasion of Ukraine, shares a 1,340-kilometer (830-mile) border with Russia.

Since joining the alliance, Helsinki has warned of increased security threats and has pledged to boost defense readiness.

Moscow has repeatedly criticized Finland's accession to NATO and warned of repercussions. 

Last week, Finland's Defense Minister Antti Hakkanen told the AFP news agency the country was "closely monitoring and assessing Russia's activities and intentions."

That followed satellite images published by the New York Times indicating expanded Russian military infrastructure near the border.

Hakkanen said Russia's moves to strengthen its armed forces in the area were "not a surprise to Finland."

Away from the land border, the Baltic Sea region is on high alert after a string of power cable, telecom link and gas pipeline outages since Russia invaded Ukraine in 2022. The NATO alliance, which Finland's neighbor Sweden joined in 2024, has boosted its presence in the maritime area with frigates, aircraft and naval drones.

In April, Finland announced plans to raise defense spending to at least 3% of GDP by 2029 and restructure its military to respond to evolving threats.

The diplomatic summons came as German Chancellor Friedrich Merz traveled to Finland to attend a summit with the prime ministers of Finland, Sweden, Norway, Denmark and Iceland.

Edited by Wesley Dockery