Russian troops continue to face sustained Ukrainian counterattacks and mounting casualties as they attempt to encircle and cut off the capital Kyiv.

Here are the latest developments on day 20 of the invasion:

Russia launched its attack in the early hours of 24 February from three main directions: north, south and east.

Targets all over the country have been attacked from land, sea and air.

Russian naval forces have also cut Ukraine off from maritime trade by controlling its Black Sea coast, according to the UK Ministry of Defence.

Russian forces are attempting to encircle and cut off the Ukrainian capital, with troops now moving towards the city from multiple positions.

Two people have been killed by a Russian airstrike that hit an apartment block in south-western Kyiv. Several other residential buildings in the Svyatoshinsky district were damaged as a result of the attack, according to emergency services.

Ukrainian generals say they are fighting to keep Russian artillery out of range of the city.

Russian forces carried out several attacks in the northwest of the city on Monday around Bucha and Irpin, but efforts to cross the Irpin River failed, according to the Institute for the Study of War (ISW).

Russian engineers unsuccessfully tried to build a pontoon bridge over the river. Ukrainian troops blew up the main bridge linking Irpin and Kyiv at the start of the war in an attempt to slow the Russian advance.

A 40-mile Russian armoured column has now dispersed into the area west of Kyiv, moving more artillery and rocket launchers to within range of the capital.

The city is bracing itself for a ground assault, with Ukrainian forces and volunteers building new defences and creating barricades on major routes to slow any Russian attack.

There were no attempts to launch operations by Russian forces to the east of the capital, where Ukrainian generals believe rivers and extensive marshland make the job of attacking Kyiv much harder.

Although Russian troops have pushed forward towards the outskirts of Kyiv, their progress in the north has been slower than in the south.

The main advance towards the capital initially came from Belarus down the west side of the Dnieper River via Chernobyl.

Russian forces have faced serious logistical problems, with many vehicles running out of fuel, and strong Ukrainian resistance. Hostomel airport has changed hands several times.

Russian troops have surrounded the city of Sumy, bombed vital infrastructure and cut off supply routes. The local governor says a humanitarian corridor has been agreed to allow people to leave the city and surrounding areas on Tuesday.

Artillery attacks on residential areas of Kharkiv are being investigated by United Nations (UN) prosecutors for possible war crimes.

Russian forces have made rapid gains across the south of the country, advancing east and west from Crimea.

In the south-east, there is growing concern for several hundred thousand civilians trapped in the port city of Mariupol, which is encircled by Russian forces and has come under heavy fire.

Russian artillery has caused widespread destruction, while Russian aircraft are increasingly involved in the assault. Chechen leader Ramzan Kadyrov says 5,000 Chechen soldiers are fighting on the Russian side near the city.

A humanitarian convoy will head to the city on Tuesday to deliver "dozens of tonnes of water, medicines and food" to people who have been trapped with dwindling supplies in freezing temperatures. Around 160 vehicles managed to leave the city on Monday, according to local officials.

The Ukrainian military says its forces have managed to fend off Russian attempts on the ground to capture the port city.

Russian forces have been heading north in the direction of Zaporizhzhia, but may struggle to take the city whilst large numbers of Russian troops remain committed to the fight in Mariupol, according to the ISW.

They have also been reinforcing positions around Mykolaiv.

The BBC's Security Correspondent Frank Gardner says the prize for Russia is the strategic port city of Odesa to the southwest, which would cut off Ukraine's access to the Black Sea.

Fighting continues in the Donetsk region. Russian forces are reported to be making steady territorial gains in the region.

The Donetsk regional governor said barely anything was left of the city Volnovakha as a result of Russian attacks.

In neighbouring Luhansk, Russian forces are reported to have made several unsuccessful attacks on Severodonetsk.

Dnipro has come under attack in recent days and is strategically important as a point of convergence for Russian troops coming from the south and east.

Since the invasion began, nearly three million people have fled Ukraine, according to the UN.

It is the fastest-growing refugee crisis in Europe since World War Two.

Unicef, the UN children's agency, believes around half of them are children and young people.

By David Brown, Bella Hurrell, Dominic Bailey, Mike Hills, Lucy Rodgers, Paul Sargeant, Mark Bryson, Zoe Bartholomew, Sean Willmott, Sana Dionysiou, Joy Roxas, Gerry Fletcher, Jana Tauschinsk and Prina Shah.

From 2 March this daily assessment differentiated between "Assessed Russian-controlled Ukrainian territory" and "Assessed Russian advances in Ukraine", the latter indicating areas where Russians are believed to have launched attacks from but which they do not control.

To show key areas where advances are taking place we are also using daily updates from the UK Ministry of Defence and BBC research. To show locations where there have been attacks or explosions we are using reports that have been verified by the BBC.

The situation in Ukraine is fast moving and it is likely there will be times when there have been changes not reflected in the maps.