headlines: Russia accused of shelling Mariupol humanitarian corridor
articles: Russia has stepped up attempts to encircle defending forces in the east of Ukraine and stood accused of shelling a humanitarian corridor out of Mariupol, as the US vowed to move “heaven and earth” to help Ukraine win the war.
  
  Amid a flurry of diplomatic activity in Moscow and Germany, a fresh wave of civilian deaths were reported across eastern Ukraine as Vladimir Putin’s forces escalated their barrage of key targets on Tuesday and appeared to renege once again on giving safe passage to women and children.
  
  Petro Andryushchenko, an adviser to the mayor of Mariupol, the besieged port city on the Sea of Azov where the remaining Ukrainian forces and civilians have been hiding out in a steel works, said the latest attempt to get people out had failed.
  
  Andryushchenko claimed that agreement on a humanitarian corridor out of the Azovstal steelworks had proven to be a “trap”, with Russian forces firing their artillery on the exit zone just moments after announcing through loudspeakers that a green corridor had been opened.
  
  Last week, Putin had ordered his troops not to storm the steel mill, but to seal it off so that “not even a fly comes through”. There are an estimated 1,000 Ukrainian soldiers in the complex, along with many of their families.
  
  Andryushchenko said that over the past 24 hours, there had been 35 airstrikes against the Azovstal plant, with one strike causing a fire to break out in one of the workshops where civilians had been hiding, leaving some under rubble.
  
  Russia’s foreign minister, Sergei Lavrov, meeting the UN secretary general in Moscow, dismissed Ukraine’s proposal to stage peace talks in the port city, saying it was a “theatrical gesture” and “they probably wanted another heartrending scene”.
  
  Russia’s apparent flouting of the agreement for a humanitarian rescue of civilians trapped in Mariupol came amid increased efforts to push on in the east of Ukraine.
  
  Pavlo Kyrylenko, the governor of the Donetsk region, reported that two people had been killed and six others wounded as “Russians continue to deliberately fire at civilians and to destroy critical infrastructure”.
  
  In the neighbouring region of Luhansk, the governor, Serhiy Haidai, said three people had died after Russian shells hit a residential building in the city of Popasna, which Russian forces have been trying to capture.
  
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  There were also reports of damage to an important bridge across the Dniester estuary linking the strategically vital region of Bessarabia to the rest of the country.
  
  Should Ukrainian forces leave Bessarabia for fear of being cut off it could become a staging post for an attack on the Black Sea city of Odesa.
  
  Russia has refocused its operations in Ukraine in recent weeks away from storming the capital, Kyiv, in the north and towards creating a Kremlin-controlled region stretching across the east and south of Ukraine.
  
  At the US Ramstein airbase in Germany, Joe Biden’s defence secretary, Lloyd Austin, attending a meeting of officials from about 40 countries, pledged more weapons to foil Putin, while Germany announced it had cleared the way for delivery of Gepard anti-aircraft guns to Ukraine.
  
  Austin said he wanted to find a “common and transparent understanding of Ukraine’s near-term security requirements because we’re going to keep moving heaven and earth so that we can meet them”.
  
  Meanwhile, the head of the UN’s atomic watchdog has condemned the Russian occupation of the Chernobyl nuclear plant, describing the situation as “absolutely abnormal and very, very dangerous”.
  
  Rafael Grossi, the International Atomic Energy Agency (IAEA) director general, spoke to reporters as he arrived at the site of the former nuclear power plant, which was occupied by Russian troops for several weeks.
  
  Grossi was heading an expert mission to Chernobyl to “deliver equipment, conduct radiological assessments and restore safeguards monitoring systems”, the IAEA said.