KYIV, Ukraine — A Russian missile struck close to a nuclear power plant in southern Ukraine Monday, not damaging its three reactors but hitting other industrial equipment in what Ukrainian authorities denounced as an act of “nuclear terrorism.”

The strike follows warnings from Russian President Vladimir Putin of possible stepped-up attacks on key Ukrainian infrastructure after his forces suffered humiliating battlefield setbacks.

The missile struck just 300 meters (yards) from the Pivdennoukrainsk nuclear plant, also known as the South Ukraine Nuclear Power Plant, according to Ukrainian nuclear operator Energoatom.

Black-and-white CCTV footage released by Ukraine’s Ministry of Defense showed two large fireballs erupting one after the other in the dark. followed by incandescent showers of sparks. A time stamp on the video read 19 minutes after midnight.

The ministry and Energoatom both called the strike “nuclear terrorism.” The Russian Defense Ministry had no immediate comment.

The nuclear plant is Ukraine’s second-largest, after the Zaporizhzhia plant that has repeatedly come under fire. Their reactors are of the same design.

The Zaporizhzhia plant, the largest in Europe, has been occupied by Russian forces since the early days of Moscow’s nearly seven-month invasion. Repeated shelling cut off its transmission lines, forcing operators to shut down its six reactors to avoid a radiation disaster. Russia and Ukraine have traded blame for the shelling. The International Atomic Energy Agency said the main transmission line was reconnected on Friday.

In delivering his warning Friday of possible ramped-up strikes on Ukrainian infrastructure, Putin claimed that his forces have until now acted with restraint against Ukrainian attempts to hit Russian facilities.

“If the situation develops this way, our response will be more serious,” Putin said.

“Just recently, the Russian armed forces have delivered a couple of impactful strikes,” he said in a reference to Russian attacks last week. ”Let’s consider those as warning strikes.”

As well as infrastructure, Russian forces also continue to pound other sites. The most recent shelling killed at least eight civilians and wounded 22 others, Ukraine’s presidential office said Monday.

Overnight, Russian forces struck Nikopol and Marhanets across the Dniper River from the Zaporizhzhia plant, damaging dozens of buildings and cutting power supplies to some sections of the cities, the presidential office said.

Russian strikes also hit Kramatorsk and Toretsk in the eastern Donetsk region, it said. In the village of Strilecha in the northeastern Kharkiv region, Russian shelling killed four medical workers while they were trying to evacuate patients from a psychiatric hospital, and wounded two patients, said Kharkiv Gov. Oleh Syniehubov.

Energoatom said the explosive force of Monday’s missile strike broke more than 100 windows at the industrial complex that includes the Pivdennoukrainsk plant. The strike also caused the temporary shutdown of a nearby hydropower plant, it said. Ukraine’s presidential office said the attack also severed three power transmission lines.

The plant sits along the Southern Bug River in the in the southern Mykolaiv region, about 300 kilometers (190 miles) south of the capital, Kyiv.

The IAEA, the United Nations’ nuclear watchdog, which has monitors at the Zaporizhzhia plant, did not immediately respond to a request for comment on the attack.

Other recent Russian strikes on Ukrainian infrastructure targeted power plants in the north and a dam in the south. They came in the wake of a sweeping Ukrainian counterattack in the east of the country that has pummeled Russian forces, reclaiming a large swath of previously occupied territory in the Kharkiv region and breaking what had largely become a stalemate in the war.

The Russian pullback marked the largest defeat for Moscow since it withdrew its forces from around Kyiv after a botched attempt to capture the capital in the invasion’s opening stage.

The setback has fueled renewed discussion among Russian nationalist critics of the Kremlin who question why Moscow failed to plunge Ukraine into darkness at the outset of the invasion by hitting all of its major nuclear power plants.