The Russian defense ministry said on Monday that the shelling of the Zaporizhzhia nuclear power plant caused smoke, which was extinguished by firefighters, TASS reported.
United Nations (UN) Secretary-General Antonio Guterres called on Monday for international inspectors to be given access to the plant after Ukraine and Russia traded accusations over shelling of Europe's largest atomic complex at the weekend.
"Any attack [on] a nuclear plant is a suicidal thing," Guterres told a news conference in Japan, where he attended the Hiroshima Peace Memorial Ceremony on Saturday to commemorate the 77th anniversary of the world's first atomic bombing.
Despite the shelling, the nuclear reactor complex was operating in "normal mode", Interfax news agency said, quoting Yevgeniy Balitsky, head of the local administration, on Monday.
Russian forces captured the plant in Ukraine's southeast in early March, shortly after Moscow's February 24 military operations on its neighbor, but it is still run by Ukrainian technicians.
Ukraine blamed Russia for renewed shelling around the plant on Saturday that had damaged three radiation sensors and injured a worker. It was the second reported hit on the plant in as many days, following damage to a power line.
Ukrainian President Volodymyr Zelenskyy, in a televised address on Sunday, accused Russia of waging "nuclear terror" that warranted more international sanctions, this time on Moscow's sprawling nuclear power sector.
The Zaporizhzhia region's Russian authority said Ukrainian forces hit the site with a multiple rocket launcher, damaging administrative buildings and a storage area.
Russia's embassy in Washington said Ukrainian artillery damaged two high-voltage power lines and a water pipeline, but critical infrastructure was unaffected.
The Kremlin said on Monday that Western countries with influence over Ukraine should push Kyiv to stop the shelling.
Media outlets were not able to verify either side's version of what happened.
Ukraine has said it is planning to conduct a major counter-offensive in the Russian-occupied south, apparently focused on the city of Kherson, west of Zaporizhzhia, and that it has already retaken dozens of villages.
Armed conflict near the Soviet-era nuclear power station has alarmed the world.
Guterres said the International Atomic Energy Agency (IAEA) needed access to the plant. "We fully support the IAEA in all their efforts in relation to creating the conditions for stabilization of the plant," he said.
IAEA Director General Rafael Mariano Grossi warned on Saturday that the latest attack "underlines the very real risk of a nuclear disaster".
(With input from agencies)