Emergency services in Moscow-occupied Ukraine said Sunday the key Kakhovka dam in the Russian-controlled region of Kherson was "damaged" by a Ukrainian strike, Russian news agencies reported.
"Today at 10:00 (0800 GMT) there was a hit of six HIMARS rockets. Air defence units shot down five missiles, one hit a lock of the Kakhovka dam, which was damaged," Russian agencies quoted local emergency services as saying.
Ukraine has in recent weeks warned that Moscow forces intended to blow up the strategic facility to cause flooding.
The RIA Novosti news agency then quoted a local Moscow-backed official saying the damage was not "critical."
"Everything is under control. The main air defense strikes were repelled, one missile hit (the dam), but did not cause critical damage," Ruslan Agayev, a representative of the Moscow-installed administration of nearby city Novaya Kakhovka told the agency.
The Kakhovka hydroelectric dam in southern Ukraine was captured by Moscow's forces at the start of their offensive. It supplies Russian-annexed Crimea with water.
Ukrainian President Volodymyr Zelensky has accused Russian troops of planning to blow it up to trigger a devastating flood.
Upstream from the dam is the Kakhovka reservoir on the Dnieper.
The reservoir can hold 18km 3 of water.
Kyiv has said that the dam bursting would cause a "catastrophe on a grand scale" and has called for an international mission to be deployed at the dam.