Skirmishes have flared on the outskirts of the Ukrainian capital as the country’s president vowed to keep battling a Russian invasion that has led to his people seeking safety underground.

The Russian assault on Kyiv has led to a curfew being announced in the city, set to last through until Monday morning.

Even as journalists were forced inside, the relative quiet of the night in Kyiv was sporadically broken by gunfire.

President Volodymyr Zelensky promised to “fight for as long as needed to liberate our country”, as he continued to press for additional international help.

Fighting on the city’s outskirts suggested that small Russian units are trying to clear a path for the main forces.

Small groups of Russian troops were reported inside Kyiv, but the UK and US said the bulk of Russian forces were 19 miles from the city’s centre as of Saturday afternoon.

Russia claims its assault on Ukraine is aimed only at military targets, but bridges, schools and residential areas have been hit since the invasion began on Thursday, with air and missile strikes and Russian troops entering Ukraine from the north, east and south.

A burning truck
A burnt-out military truck in the street in Kyiv (AP)

Ukraine’s health minister reported that 198 people, including three children, had been killed and more than 1,000 others had been wounded during Europe’s largest land conflict since the Second World War.

It is unclear whether those figures included both military and civilian casualties.

In Kyiv, a missile struck a high-rise apartment building in the south-western outskirts near one of the city’s two passenger airports, leaving a jagged hole of ravaged apartments over several floors.

A rescue worker said six civilians were injured.

Mr Zelensky reiterated his openness to talks with Russia in a video message on Saturday, saying he welcomed an offer from the leaders of Turkey and Azerbaijan to organise fresh diplomatic efforts.

That came a day after Mr Zelensky offered to negotiate a key Russian demand: that Ukraine should abandon ambitions of joining Nato.

Ukrainian soldiers on patrol in Kyiv
Ukrainian soldiers on patrol in Kyiv (Efrem Lukatsky/AP)

Russian president Vladimir Putin sent troops into Ukraine after he spent weeks denying this was his intention, all the while building up a force of almost 200,000 soldiers along the countries’ borders.

He claims the West has failed to take seriously Russia’s security concerns about Nato, the Western military alliance that Ukraine aspires to join. But he has also expressed scorn about Ukraine’s right to exist as an independent state.

Mr Putin has has not disclosed his ultimate plans for Ukraine, but Western officials believe he is determined to overthrow Ukraine’s government and replace it with a regime of his own, redrawing the map of Europe and reviving Moscow’s Cold War-era influence.

Ukraine Invasion
A damaged apartment building in Kyiv (Efrem Lukatsky/AP)

A senior US defence official said more than half of the Russian combat power that was massed along Ukraine’s borders had entered Ukraine, and that Russia has had to commit more fuel supply and other support units inside Ukraine than originally anticipated.

Ukraine’s infrastructure ministry said a Russian missile was shot down before dawn on Saturday as it headed for the dam of the sprawling water reservoir that serves Kyiv, and Ukraine said a Russian military convoy was destroyed near the city early on Saturday.

Footage showed soldiers inspecting burned-out vehicles after Ukraine’s 101st brigade reported destroying a column of two light vehicles, two trucks and a tank. The claim could not be verified.

Highways into Kyiv from the east were dotted with checkpoints manned by uniformed Ukrainian troops and young men in civilian clothes carrying automatic rifles. Low-flying planes patrolled the skies, though it is unclear if they were Russian or Ukrainian.

Ukrainian refugees
Refugees fleeing conflict in neighboring Ukraine arrive to Przemysl, Poland (AP)

In addition to Kyiv, the Russian assault appeared to focus on Ukraine’s coastline, which stretches from near the Black Sea port of Odesa in the west to beyond the Azov Sea port of Mariupol in the east.

If the Russian troops succeed, Ukraine would be cut off from access to all of its sea ports, which are vital for its economy.

In Mariupol, Ukrainian soldiers guarded bridges and blocked people from the shoreline amid concerns the Russian navy could launch an assault from the sea.

Fighting also raged in two territories in eastern Ukraine that are controlled by pro-Russian separatists. Authorities in the city of Donetsk said hot water supplies to the city of about 900,000 were suspended because of damage to the system by Ukrainian shelling.

Ukraine subway
A girl paints on a note book next to her mother as they shelter in the Kyiv subway (AP)

The US government urged Mr Zelensky to evacuate Kyiv but he turned down the offer, according to a senior American intelligence official.

In a video recorded in Kyiv, Mr Zelensky declared: “We aren’t going to lay down weapons. We will protect the country.

“Our weapon is our truth, and our truth is that it’s our land, our country, our children. And we will defend all of that.”

The conflict has driven thousands of Ukrainians from their homes in search of safety.

UN officials said more than 150,000 Ukrainians had left the country for Poland, Moldova and other neighbouring nations and estimated four million could flee if the fighting escalates.

Officials in Kyiv have urged residents to seek shelter, to stay away from windows and to take precautions to avoid flying debris or bullets.

The US military has announced 350 million dollars (£261 million) in assistance to Ukraine, including anti-tank weapons, body armour and small arms.

Germany likewise said it would send missiles and anti-tank weapons to the country, in a significant shift.

The US and its allies have beefed up troops on Nato’s eastern flank but so far have ruled out deploying troops to fight Russia.

Ukraine exodus
People gather to catch a train and leave Ukraine for neighbouring countries (AP)

Instead, the US, the European Union and other countries have slapped wide-ranging sanctions on Russia, freezing the assets of Russian businesses and individuals including Mr Putin and his foreign minister, Sergei Lavrov.

Mr Zelenskyy has appealed for tougher sanctions.

Among the possibilities that remain to block the Kremlin’s access to hundreds of billions in cash are sanctioning the Russian Central Bank, and cutting Russia from the Swift international payment system.

However, a senior Russian official shrugged off sanctions as a reflection of Western “political impotence”.

Dmitry Medvedev, the deputy head of Russia’s security council, warned that Moscow could react to the sanctions by opting out of the last remaining nuclear arms pact, freezing Western assets and cutting diplomatic ties with nations in the West.

“There is no particular need in maintaining diplomatic relations,” Mr Medvedev said. “We may look at each other in binoculars and gunsights.”