KYIV, Ukraine (AP) — Ukraine’s two largest cities came under attack from Russian hypersonic ballistic missiles on Tuesday morning, killing at least four people and injuring almost 100, officials said, as the war approached its two-year milestone and the Kremlin’s forces stepped up their winter bombardment of urban areas.

Ukraine President Volodymyr Zelenskyy said on his Telegram channel that four civilians were killed and 92 injured in the capital, Kyiv, and in northeastern Kharkiv as hypersonic Kinzhal missiles that can fly at 10 times the speed of sound slammed into city blocks.

Russia fired almost 100 missiles of various types, Zelenskyy said on X, formerly Twitter. He claimed that at least 70 missiles were shot down, almost all of them in the Kyiv area, and said Western-supplied air defense systems such as Patriots and NASAMS had saved hundreds of lives.

Russia’s Defense Ministry said it had launched missile and drone strikes on military industrial facilities in and around Kyiv. Depots storing missiles and munitions supplied by Ukraine’s Western allies were also targeted, it said.

“The goal of the strike has been achieved, all the targets have been hit,” it said without elaborating. It was not possible to independently verify either side’s claims.

Since Sunday, Zelenskyy said, Russian forces have launched about 170 Shahed drones and “dozens of missiles of various types” in an onslaught against Ukrainian targets. Most were aimed at civilian areas, he said.

The Kh-47M2 Kinzhal is an air-launched hypersonic ballistic missile. Russian forces rarely use such expensive missiles against Ukraine due to their limited stocks.

The attacks created a desolate morning scene in the capital, with most cafes and restaurants remaining closed. Many people opted to stay indoors or seek refuge in shelters as powerful explosions shook the city from early morning.

Air raid sirens blared for nearly four hours, and the city’s subway stations — which function as shelters — were crowded.

After the Ukrainian air force issued warnings about incoming hypersonic missiles, people wearing pajamas underneath their coats took sleeping bags, mats and their pets to subway stations while loud explosions echoed above the city. At one of the central stations, called Golden Gates, hundreds of people filled the spacious underground areas while trains continued to run.

“Perhaps today was the most frightening because there were so many explosions,” said resident Myroslava Shcherba.

The barrage extended Russia’s escalated attacks on Ukraine that began Friday with its largest single assault on Ukraine since the war started, in which at least 41 civilians were killed.

The next day, shelling of the Russian border city of Belgorod killed more than two dozen people. Russia blamed Ukraine for the attack and has struck back repeatedly since.

The attack on Belgorod was one of the deadliest to take place on Russian soil since Moscow’s full-scale invasion of Ukraine started more than 22 months ago. Russian officials said the death toll stood at 25 as of Monday, including five children.

Cities across western Russia have regularly come under drone attacks since May, although Ukrainian officials never acknowledge responsibility for strikes on Russian territory or the annexed Crimean Peninsula.

“They want to intimidate us and create uncertainty within our country. We will intensify strikes. Not a single crime against our civilian population will go unpunished,” Putin said Monday, describing the barrage of Belgorod as a “terrorist act.”

Russia launched about 90 Shahed-type drones across Ukraine on Monday.

Putin accused Western nations of using Ukraine to try to “put Russia in its place.” While vowing retribution, he insisted Russia would only target military infrastructure in Ukraine. However, Ukraine reports civilian casualties from daily Russian attacks, which have hit apartment buildings, shopping centres and residential areas in small communities.

In other developments, Russia’s Defense Ministry said one of its warplanes accidentally released munitions over the Russian village of Petropavlovka in the southwestern Voronezh region Tuesday, causing no injuries but damaging six houses. The ministry said a commission has been created to determine the cause of the accident and assess the damage. It didn’t say what type of munition the warplane dropped.

In April, munitions accidentally released by a Russian warplane caused a powerful blast in the border city of Belgorod, damaging several cars and slightly injuring two people.

Air raid sirens sounded Tuesday in Belgorod, which is near the border with Ukraine. Russia’s Defense Ministry said air defense systems shot down four missiles fired by a Ukrainian Vilkha multiple rocket launcher.