Vasily Malayev, a regional representative of Russia's Federal Security Service branch devoted to border security, said 30 shells had landed in a village in the region.
He added: "There are no victims or casualties as a result of the shooting on Russian territory from the Ukrainian side."
He earlier said about 40 shells had come across the border.
Both Moscow and Kiev have accused the other of shooting across the border and Ukraine says missiles shot from Russia may have downed two of its fighter jets this week.
Both Kiev and Moscow deny the accusations. Russian president Vladimir Putin warned earlier this month of "irreversible" consequences after cross-border shelling that hit two houses in Rostov province, killing one man.
Russia's Chief of General Staff said it had proof Ukraine had used phosphorus bombs that can kill through burns or smoke inhalation.
Earlier allegations of the use of the weapon were never proved and Kiev quickly denied this accusation.
Kiev's military spokesman Vladislav Seleznyov said: "It's complete nonsense. We don't use phosphorus bombs. We simply don't have them. We use flares, but they have no relation to phosphorus bombs."
Russia also claimed the US was trying to influence international opinion through unfounded insinuations and anti-Russian rhetoric over the crisis in Ukraine.
Russia's Foreign Ministry said in a statement: "We deny the unfounded public insinuations that State Department Spokeswoman Marie Harf repeats day after day."
Ms Harf claimed at a briefing in Washington on Thursday that Russia was firing artillery across the border into Ukraine to target Ukrainian military positions in the conflict against pro-Russian separatists battling against Kiev.