Photo taken on April 19, 2016 shows a warning sign in the forest near Chernobyl, Ukraine. (Xinhua/Dai Tianfang)

MOSCOW, Nov. 21 (Xinhua) -- Russia's state nuclear corporation Rosatom Tuesday denied that its facilities had caused a slight increase in the volume of the radioactive element ruthenium-106 in Russia and other parts of Europe between September and October.

There have been no lapses in equipment operation or any violation of operational safety at any of Rosatom facilities, it said in a statement.

The radiation situation around all Russian nuclear facilities is normal and corresponds to the natural radiation background, it said.

On Oct. 8, the German Federal Office for Radiation Protection and the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety said in a joint statement that a slight increase in radioactive ruthenium-106, which posed no threat to public health, was detected in Germany, Austria, Switzerland and Italy.

It said the increase originated from the southern Urals region on the border between Russia and Kazakhstan and could be the result of an accident at a nuclear facility.

Russia has one of its largest nuclear facilities in the region, namely Mayak, housing plutonium production reactors and a reprocessing plant built between 1945 and 1948 as part of the Soviet atomic bomb project.

"In 2017, there was no production of ruthenium-106 sources at the Mayak Production Association," said Rosatom, owner of the facility.

Russian meteorological service Roshydromet and Russian consumer safety watchdog Rospotrebnadzor confirmed an excessive level of ruthenium-106 in various Russian regions between Sept. 25 and Oct. 6.

But both said the volume was still well below a dangerous level.

"The published data do not allow us to establish the location (country) of the pollution source," Roshydromet head Maxim Yakovenko said.

So far, it remains unclear what caused the pollution.