A man armed with four handguns killed two people and wounded five others when he fired into a crowd outside a high school graduation ceremony in Richmond, Virginia, on Tuesday, police said.

Police said they arrested one suspect, a 19-year-old man who knew one of the victims and shot at him amid the crowd that had just emerged from the Huguenot High School’s commencement ceremony inside a theater on the campus of Virginia Commonwealth University, Reuters reported.

The suspect was likely to be charged with two counts of second-degree murder in addition to other offenses, interim Richmond Police Chief Rick Edwards told a press conference.

Edwards called the shooter’s behavior “disgusting and cowardly,” since his dispute appeared to be with just one person.

“When you have a crowd like this, innocent people are going to be caught up in the mayhem, and that’s what happened today. ” Edwards said. “Obviously, this should have been a safe space…It’s just incredibly tragic that someone decided to bring a gun to this incident and rain terror on our community.”

The United States has grown accustomed to mass shootings in public places such as schools, shopping centers and churches.

The mass shooting was the country’s 279th in the first 157 days of 2023, according to the Gun Violence Archive, using the definition of four or more people are shot or killed in a single incident, not including the shooter.

The deceased were men aged 18 and 36, Edwards said. He did not confirm a WWBT television news report that the victims were father and son.

Among the wounded, a 31-year-old man suffered life-threatening injuries and four other males aged 14, 32, 55 and 58 were expected to survive, Edwards said.

In addition, a 9-year-old girl was struck by a car in the chaos that ensued, and multiple other people were injured in falls or suffered from anxiety, Edwards said.

The suspect fled the scene on foot and was captured in possession of four handguns, three of which may have been fired, he said, stressing that it was too early in the investigation to be certain.

A torrent of water burst through a huge dam on the Dnipro River that separates Russian and Ukrainian forces in southern Ukraine on Tuesday, flooding a swathe of the war zone and forcing villagers to flee.

Ukraine and its Western allies accused Russia of blowing up the dam in a deliberate war crime. The Kremlin said it was Ukraine that had sabotaged the dam, to distract attention from a counteroffensive Moscow claims is faltering. Some Russian-installed officials said the dam had burst on its own, Reuters reported.

Neither side offered immediate public evidence of who was to blame. The Geneva Conventions explicitly ban targeting dams in war, because of the danger to civilians posed by destruction of such “works and installations containing dangerous forces”.

By mid-morning in the city of Kherson on the Ukrainian-held side, a pier on a tributary of the Dnipro had already been submerged by the surge climbing the banks.

“The water level has so far risen one meter,” resident Oleksandr Syomyk told Reuters. “We’ll see what happens next but we hope for the best.”

The Nova Kakhovka dam supplies water to a swathe of southern Ukraine’s agricultural land, including the Russian-occupied Crimean peninsula, as well as cooling the Russian-held Zaporizhzhia nuclear plant. The vast reservoir behind it is one of the main geographic features of southern Ukraine, 240 km long and up to 23 km wide.

A swathe of countryside lies in the flood plain below, with villages on the Russian-held southern bank seen as particularly vulnerable.

The destruction of the dam creates a new humanitarian disaster in the center of the war zone and transforms the front lines just as Ukraine is unleashing a long-awaited counteroffensive to drive Russian troops from its territory.

Russia has controlled the dam since early in the war, although Ukrainian forces recaptured the northern side of the river last year. Both sides had long accused the other of planning to destroy it.

“Russian terrorists. The destruction of the Kakhovka hydroelectric power plant dam only confirms for the whole world that they must be expelled from every corner of Ukrainian land,” President Volodymyr Zelenskiy wrote on the Telegram messaging app.

Russians had “carried out an internal detonation of the structures” of the dam. “About 80 settlements are in the zone of flooding,” he said on Telegram.

NATO’s Secretary-General Jens Stoltenberg called it “an outrageous act, which demonstrates once again the brutality of Russia’s war in Ukraine”.

Kremlin spokesman Dmitry Peskov told a regular news briefing: “We can state unequivocally that we are talking about deliberate sabotage by the Ukrainian side.”

The U.N. nuclear watchdog said the Zaporizhzhia power plant should have enough water to cool its reactors for “some months” from a separate pond located above the reservoir, and called for the pond to be spared.

The water level at the town immediately adjacent to the breached dam could rise by up to 12 meters, its Russia-installed mayor, Vladimir Leontyev, said on Telegram.

Video showed water surging through the remains of the dam – which is 30 meters tall and 3.2 km long.

Some 22,000 people living across 14 settlements in Kherson region are at risk of flooding, Russia’s RIA news agency quoted the Moscow-installed head of the region as saying. Kherson is one of five Ukrainian regions Moscow claims to have annexed.

Russia’s Defense Ministry announced early Monday its forces had thwarted a large Ukrainian attack in the eastern province of Donetsk, though it’s unclear if this was the start of a Ukrainian counteroffensive.

The ministry, in a rare early morning video, said its forces pushed back a “large scale” Ukrainian assault on Sunday at five points in southern Donetsk, one of four Ukrainian regions Russia illegally annexed last fall, Associated Press reported.

“The enemy’s goal was to break through our defenses in the most vulnerable, in its opinion, sector of the front,” said the ministry’s spokesman, Igor Konashenkov. “The enemy did not achieve its tasks. It had no success.”

Konashenkov said 250 Ukrainian personnel were killed, and 16 Ukrainian tanks, three infantry fighting vehicles and 21 armored combat vehicles were destroyed.

Ukraine didn’t comment, and often waits until the completion of its military operations to confirm its actions, imposing news blackouts in the interim. It was unclear why the Russian Defense Ministry waited until Monday morning to announce the attack, which it said started Sunday morning.

For months, Ukrainian officials have spoken of plans to launch a spring counteroffensive to reclaim territory Russia has occupied since invading Feb. 24, 2022, as well as the Crimean Peninsula it seized in 2014.

But they’ve given confusing signals about what would constitute a counteroffensive — preliminary, limited attacks to weaken Russian forces and military facilities or a full-fledged simultaneous assault across the entire 1,100-kilometer front line.

The Russian Defense Ministry spokesman said Ukraine used six mechanized and two tank battalions in the attack, and it released a video claiming to show destruction of some of the equipment in a field.