What has happened so far in the Russian invasion of Ukraine

After a weekend of fierce fighting, the assault on Ukraine from Russia has continued past a fourth day.

For readers just joining us, here's what happened on Sunday:

• Intense fighting continued through the weekend, with Russian forces targeting cities in Ukraine, but ultimately failing to hold the key city of Kharkiv, in the northeast of the country, and its second largest
• However, the assault from Russia continues from almost all directions, and Kremlin forces were said to be making better progress from the south, besieging the port cities of Kherson and Berdyansk, on two parts of the Black Sea
• Ukrainian President Volodymyr Zelensky announced plans to meet a Russian delegation on the Ukrainian-Belarusian border after talks with Belarusian leader Alexander Lukashenko. No timeline was offered and the situation is vexed, given Belarusian support for Putin's invasion
• Earlier, the Ukrainian government said it had petitioned the International Court of Justice to bring charges against Russia for its invasion
• European and US allies accused the Kremlin of ratcheting up tensions further after President Putin put Russian nuclear defences on "special alert"
• Residents in the capital city of Kyiv remain under curfew as it braces for further assault, with reports of more Russian troops headed to the city
• Russians are braced for financial chaos ahead of markets opening on Monday after tough sanctions were announced over the weekend that would freeze Russian banks out of the international financial system

Source: BBC