Estonian border guards have accused their Russian counterparts of removing a set of buoy markers on the Narva River between the two countries.

The move comes after media reports that unilateral plans to adjust Russia’s maritime borders with  Lithuania and Finland were published on the Russian defence ministry website and then later apparently withdrawn.

Baltic politicians view the Russian actions as part of Moscow’s hybrid warfare on the Eastern Flank, designed to unsettle its Nato neighbours.

“Russia uses border issues as a means to create fear and anxiety,” Estonian Prime Minister Kaja Kallas said at a press conference in Tallinn on May 23. “We will approach this incident soberly, in a balanced way, if needed also in communication with partners and allies.”

Estonia's border guard service accuse Russian officials of carrying off 24 of 50 buoys helping to separate the two countries on the waterway at 3 a.m. on May 23.

The markers had been placed within Estonian waters by authorities over the last 10 days.

Vilnius insists it wants a 'unified response' from the European Union and Nato, Prime Minister Ingrida Simonytė said, LRT.lt, the website of Lithuania’s national broadcaster LRT, reported on May 23.

 “We continue to work with our neighbours and partners at both the EU and Nato levels to ensure a unified response to the situation,” Simonyte told reporters on May 23. “I believe [Russia’s] aim is to create uncertainty about what is being done.”

According to a document drafted by the Russian Defence Ministry and quoted by The Moscow Times, the Kremlin intends to declare part of the Baltic Sea east of the Gulf of Finland, as well as near the towns of Baltiysk and Zelenogradsk in the Kaliningrad region, as its internal maritime waters.

The document by the Russian defence ministry suggests that on the border with Lithuania, the Curonian Spit area, Cape Taran, the area south of Cape Taran and the Baltic Spit would be revised.

Following the report, the Baltic and Finnish leaders said they were cooperating and gathering information and urged against unnecessary confusion.

The Finnish broadcaster YLE reported later that information about plans to change the maritime borders with Finland and Lithuania had disappeared from the Russian defence ministry’s website.

The document was removed from the website after a military diplomatic source told Russian news agencies that Moscow had no intention of revising the borders in the Baltic Sea.

Finnish premier Petteri Orpo later said that Lithuania was overreacting.

Simonyte said that the Kremlin’s plans remain unclear.

“I think the Russian authorities deliberately want this to be impossible to clarify; they want it to be vague, to cause anxiety and fear,” she said, adding that there was no reason for concern.

Kremlin spokesman Dmitri Peskov said on Wednesday that there was “nothing political” about the plans. He added, however, that “the level of confrontation in the region requires taking measures to ensure the country’s security”.

A Russian representative was on May 22 summoned to Lithuania’s foreign ministry to explain the plans to redraw maritime borders, LRT.lt said.