Following a torrent of air raids on cities and military bases around the country, invading Russian forces have closed in on Ukraine’s capital in an apparent encircling strategy.

According to the Reuters news agency, frequent artillery booms could be heard in Kyiv in the early hours of Saturday, coming from an unnamed site some distance from the city centre.

The invasion of Ukraine began early Thursday with missile attacks on cities and military posts, followed by a multipronged ground assault that rolled troops in from separatist-held territory in the east, Crimea in the south, which Russia invaded in 2014, and Belarus in the north.

The Western-predicted attack amounts to Europe’s most important ground confrontation since World War II. It is unclear how much Russian forces have captured or how many people have been killed.

Here is what we know about the conflict so far:

‘This night they will storm’

With signals that Russia is attempting to destabilise him, Ukrainian President Volodymyr Zelenskyy informed European Union leaders in a video link-up from his bunker late Thursday that it might be the last time they saw him alive.

However, Zelenskyy broadcast a video of himself and senior aides outside the presidential office in Kyiv on Friday to convince Ukrainians that he and other top officials would remain in the city.

He later called for a cease-fire and warned of an oncoming Russian assault on Kyiv and other cities across the country in a sombre message.

“They’re going to storm tonight,” he said. “We must persevere tonight.”

Russian troops march on

The Russian military announced on Friday that it has surrounded the cities of Sumy and Konotop in northeastern Ukraine, but that it was “taking precautions to safeguard civilian safety.”

Major General Igor Konashenkov, a spokesman for Russia’s Defense Ministry, said their forces had so far destroyed 211 Ukrainian military installations, including 17 command centres, 19 air defence missile systems, 39 radar units, 67 tanks, and six jets.

The Russian military also claimed to have taken control of a vital airport outside of Kyiv, allowing it to quickly assemble soldiers to take the capital.

The Russian military announced late Friday that it had taken control of Melitopol, a city near the Azov Sea. The claim could not be independently verified right away.

The Ukrainian military said it shot down a Russian transport jet transporting paratroopers near Vasylkiv, a city 40 kilometres (25 miles) south of Kyiv. It was unclear how many people were on board, but the II-76 can transport up to 125 paratroopers.

‘Overall mood one of horrendous fear’

As the second day of Russia’s invasion began, terrified citizens were put in danger as artillery shells rained down on several residential buildings on Kyiv’s outskirts.