Russia has launched a wide-ranging attack on Ukraine, hitting cities and bases with airstrikes or shelling as civilians piled into trains and cars to flee. Ukraine’s government pleaded for help as it said Russian tanks and troops rolled across the border in a “full-scale war” that could rewrite the geopolitical order.

“Russia has embarked on a path of evil, but Ukraine is defending itself and won’t give up its freedom,” Ukrainian President Volodymyr Zelenskyy tweeted.

After Russian President Vladimir Putin declared war in a pre-dawn televised address, explosions and gunfire were heard throughout the morning in Kyiv, a city of 3 million people.

Missiles rained down on Ukrainian targets and authorities reported columns of troops pouring across Ukraine’s borders from Russia and Belarus to the north and east, and landing on the southern coasts from the Black Sea and Azov Sea.

Fierce fighting was taking place in the regions of Sumy and Kharkiv in the northeast, Kherson and Odessa in the south, and at a military airport near the capital Kyiv, an adviser to the Ukrainian presidential office said.

Zelenskyy said troops were trying to fend off Russians attempting to capture the Chernobyl nuclear power plant, just 60 miles north of the capital.

In Kyiv, queues of people waited to withdraw money and buy supplies of food and water. The highway heading west out of the city was choked with traffic across five lanes as residents fled.

“We’re afraid of bombardments,” said Oxana, stuck in her car with her three-year-old daughter in the backseat. “This is so scary.”

Biden called the Russian action an “unprovoked and unjustified attack”. EU Commission chief Ursula von der Leyen said the bloc would impose a severe new round of sanctions.

EU foreign affairs chief Josep Borrell said: “These are among the darkest hours of Europe since the Second World War.”