MOSCOW, April 27./TASS/. Tension is visibly growing in Odessa ahead of May 2, marking two years since the Odessa massacre; the paramilitary battalions Aidar and Azov, as well as the Right Sector movement have become increasingly active, Russian Foreign Ministry spokeswoman Maria Zakharova told a briefing on Wednesday.

"Alarming reports have been coming from Odessa of late, tension is visibly growing in the city," the diplomat said. "We all know that unfortunately, on May 2 we will mark two years after a tragedy at the Trade Unions House, where dozens of civilians died in the blaze, were killed by nationalists, radicals," she went on.

"Once again reports come that trained militants from the groups ‘notorious’ for their crimes are being gradually concentrated in the city," she said, referring to the Aidar and Azov battalions, as well as the radical Right Sector outlawed in Russia.

"Additional forces of the Ukrainian National Guard is moved into the city, the city police are getting ready for having wounded persons," she went on. "In the past two years after the tragedy, the Ukrainian authorities have failed, or other failed or were unwilling, the second is more likely, to carry out a thorough objective probe into the crime with the aim to clarify all circumstances of that tragedy and to strictly punish those responsible," she added.

"Clear preparations of the present Ukrainian authorities for whipping up tension and organizing new provocations cannot but cause alarm," Zakharova said. "We expect that adequate politicians in Odessa, if it still has such, will manage to avert a new tragedy, prevent a new spiral of civil confrontation," the diplomat said.

The tragedy at the Odessa House of Trade Unions occurred on May 2, 2014. A sign-up campaign in support of a referendum turned into clashes between nationalist activists of the Right Sector and the Maidan self-defense groups on the one side and federalization supporters on the other side. The clashes resulted in the local House of Trade Unions being set on fire. More than 200 people were injured in the tragedy while 48 lost their lives.