The U.N.'s nuclear watchdog on Thursday reported powerful explosions near Ukraine's Russian-occupied Zaporizhzhia nuclear power station and renewed calls for a security zone around the plant.
A Russian official dismissed the comments by Rafael Grossi, head of the International Atomic Energy Agency (IAEA), saying they suggested Moscow could not uphold nuclear safety.
Russian forces seized the plant in early March, soon after invading neighbouring Ukraine. Russia and Ukraine have accused each other of firing around it near the front lines, prompting the IAEA to place experts at all of Ukraine's five nuclear stations.
Grossi, who visited Ukraine last week, said IAEA monitors routinely reported explosions near the plant.
"Yesterday, eight strong detonations were heard at around 10 a.m. local time, causing office windows at the plant to vibrate, and more were audible today," he said in a statement.
But Renat Karchaa, an adviser to the head of Rosenergoatom, the company operating Russia's nuclear plants, said Grossi's comments were unfounded.
"I can only describe this as a provocation. Before you provide such information you need to check it and establish that it is not based on rumour," Tass quoted him as saying.
"On the one hand, they want to show that they are doing something useful. On the other, they are again sowing doubt in Western public opinion that somehow Russia cannot cope with upholding nuclear safety."
Karchaa's acerbic tone was somewhat unusual. Russian officials have sought to ensure Western countries that they are maintaining safety standards and continue to work with the IAEA.
In his statement, Grossi said he had discussed the proposed zone with the European Union in Brussels this week and would have new talks with Moscow.
(Reporting by Ron Popeski; Editing by David Ljunggren and Grant McCool)
