Ukraine and Russia-installed local officials blamed each other for a renewed shelling of the Zaporizhzhia nuclear power complex in southern Ukraine on Thursday.
UN Secretary-General Antonio Guterres called on Thursday for an immediate end to military activity near the plant, the largest in Europe, which Russia seized in March.
Ukraine's Energoatom said the plant's area was struck five times on Thursday, including near the site where radioactive materials are stored, but nobody were injured and radiation levels remained normal.
Meanwhile, the Russian-installed local officials said Ukraine shelled the plant for the second time in one day, disrupting the shift changeover of power plant workers.
Vladimir Rogov, a member of the Russian-installed regional administration, also wrote on Telegram that at least three strikes were near the radioactive isotope storage facility.
Reuters could not independently verify the reports of either side.
The Zaporizhzhia plant area was also hit by shelling last weekend, with side trading blame.
The plant was captured by Russian forces in the opening stages of the war following Russia's Feb. 24 invasion but it is still run by its Ukrainian technicians.
Ukrainian Foreign Minister Dmytro Kuleba called on Thursday for the International Atomic Energy Agency to send a mission to the plant to assess the safety situation as soon as possible.
The Vienna-based UN nuclear watchdog has previously condemned the shelling of the plant, warning that it could cause a nuclear disaster.