Ukraine round-up: Putin defends 'necessary' invasion and Kyiv averts cyber-attack

Russia's President, Vladimir Putin, has chosen his public appearances carefully throughout the conflict in Ukraine.

On day 48 of the war, he held a press event at a spaceport in Russia's east to say his country would fight on until it achieved its goals.

He set out why he believed the invasion was necessary, repeating disproven claims that genocide was taking place against Russian-speakers in Ukraine.

The aim, he said, was to "help people".

"It's clear that we didn't have a choice. It was the right decision," Mr Putin said today about the invasion. "The goals are perfectly clear, they are noble."

You can read our full story of the event here

President Putin's goal now seems to be capturing the eastern Donbas region.

Russian military planners are sending forces to the region, where Kyiv says it's preparing for the next stage of the invasion to focus.

As hundreds of thousands of civilians escape for safety elsewhere, satellite images show large columns of Russian vehicles heading towards the Donbas in preparation for battle.

Fighting in the coming weeks is expected to become even more deadly, as the BBC's Jonathan Beale reports from the ground.

President Putin's comments also come as the cost to Russia becomes more and more clear.

A row of freshly dug military graves has appeared in recent weeks in Stavropol cemetery in southwestern Russia.

All of the soldiers buried here died after 24 February, the date of what President Putin called a "special military operation" in Ukraine began.

Mourners who are paying tribute to lost ones refuse to believe that accusations of Russian soldiers committing war crimes could be true.

"They'll accuse Russia of anything," one grieving widow tells the BBC's Russia Editor Steve Rosenberg.

Ukrainian forces in the besieged city of Mariupol allege Russia targeted their soldiers with chemical weapons, but it is still not clear what happened.

The US and Britain say they are looking into the reports of a chemical attack. But right now no evidence has been presented to prove if it did take place.

Western nations have warned that the use of chemical weapons would mark a dangerous escalation of the conflict and have pledged to take action if Russia carries out such attacks.

Our Security Correspondent Frank Gardner has been looking at how we would know chemical weapons have been used.

Hackers who could be linked to the Russian military launched a failed cyber-attack against one of Ukraine's largest energy companies.

Malicious software targeting an energy sub-station was identified and neutralised, the government in Kyiv says - preventing power from being cut to millions.

It's the most serious hacking attempt on Ukraine since the invasion began..

The Ukrainian mother who scrawled contact details on her two-year-old daughter's back while fleeing Kyiv has described her desperation.

"In case of our death, she could be found and would know who she is," Sasha Makoviy told The World Tonight on BBC Radio 4.

The family, who is now safe, was worried that little Vira could become separated during their escape and would never know who her family was.