Ukraine and Russia: What you need to know right now

* The use of nuclear weapons is a question of global security - this is no longer just about Ukraine, presidential adviser Mikhailo Podolyak told the Swiss Blick newspaper. FIGHTING * Ukrainian President Volodymyr Zelenskiy described the military situation in eastern Ukraine's Donetsk region as difficult and said late on Monday it was the country's "No. 1 goal" because it was also Russia's No. 1 goal. * Ukraine also reported fierce fighting in Kherson in the south, where it is trying to cut off Russian occupying forces.

Europe is investigating leaks in two Russian gas pipelines that churned up the Baltic Sea and raised concerns from Copenhagen to Moscow about sabotage on infrastructure at the heart of an energy standoff since Russia invaded Ukraine. GAS LEAKS

* Gas bubbles from the damaged Nord Stream 2 pipeline measure more than 100 metres in diameter, the Danish Energy Authority said. The leak will continue for several days and perhaps even a week, its head told Reuters. * Poland said the leaks were caused by sabotage linked to the situation in Ukraine, while Denmark and Russia, which slashed its gas deliveries to Europe after Western sanctions, said sabotage could not be ruled out. None of the countries said who might be behind any foul play.

* Ukrainian presidential adviser Myhailo Podolyak said the leak was "a terrorist attack planned by Russia and an act of aggression towards the EU". He did not provide any evidence in his statement on Twitter, which also called for more arms. ANNEXATION PLANS, NUCLEAR THREAT

* An ally of President Vladimir Putin issued a stark new nuclear warning to Ukraine and the West as Russia began releasing results of referendums it bills as a prelude to it annexing four Ukrainian regions. * First partial results from votes cast inside Russia on whether the four Russian-occupied regions of Ukraine should be incorporated into Russia showed overwhelming majorities in favour, Russian state news agency RIA reported.

* Ukraine urged the European Union to impose economic sanctions on Russia to punish it for staging the annexation votes, which it said would not change Ukraine's actions on the battlefield, where it is staging a counteroffensive. * Ukrainians who help Russian-backed referendums to annex large swathes of the country will face treason charges and at least five years in jail, Ukraine's presidential adviser said.

* Putin is likely to announce the accession of occupied regions of Ukraine to the Russian Federation during his address to parliament on Sept. 30, the British Ministry of Defence said. * The use of nuclear weapons is a question of global security - this is no longer just about Ukraine, presidential adviser Mikhailo Podolyak told the Swiss Blick newspaper.

FIGHTING * Ukrainian President Volodymyr Zelenskiy described the military situation in eastern Ukraine's Donetsk region as difficult and said late on Monday it was the country's "No. 1 goal" because it was also Russia's No. 1 goal.

* Ukraine also reported fierce fighting in Kherson in the south, where it is trying to cut off Russian occupying forces. It was not possible to verify the battlefield reports.

RUSSIAN MOBILISATION * The number of Russians entering the European Union has jumped after a partial military mobilisation ordered by Moscow, and illegal crossings are likely to increase should Russia decide to close the border for potential conscripts, EU border agency Frontex said.

* Nikita, a 24-year-old from the Russian city of Voronezh, drove up to a remote border crossing with Kazakhstan. Around 500 cars were already in line. His escape was part of a vast exodus

from Russia that has seen thousands of military-age men make for the borders with Finland, Georgia, Kazakhstan and Mongolia. On Monday, Novaya Gazeta Europe reported that 261,000 men had left Russia since mobilisation was declared, citing a Kremlin source. QUOTE

"Today we faced an act of sabotage, we don't know all the details of what happened, but we see clearly that it's an act of sabotage, related to the next step of escalation of the situation in Ukraine." -Polish Prime Minister Mateusz Morawiecki, referring to the Russian gas pipelines.

(This story has not been edited by Devdiscourse staff and is auto-generated from a syndicated feed.)