Most of the people killed inside the building were likely separatists although the identities have not been fully reported yet. TSN.ua is reporting 15 were Russian and 5 were from Transnistria(an autonomous part of Moldova, where Russian military is housed).
At least 31 people have been killed in a fire in an official building amid violence in Odessa in south-west Ukraine, the interior ministry says.
The deaths came as pro-Russian protesters clashed with Ukrainian government supporters in the city.
Officials said some people were overwhelmed by smoke and others died after they jumped from the building.
Earlier President Oleksandr Turchynov said many separatists had been killed in a government offensive in Sloviansk.
Activists have seized scores of government buildings and detained observers in eastern Ukraine.
The fire broke out in Odessa’s Trade Unions House, the regional office of Ukraine’s interior ministry said. It did not give details of how the blaze started.
The exact sequence of events is still unclear, but reports suggest the separatists had barricaded themselves inside the building and both sides were throwing petrol bombs.
The interior ministry gave a toll of at least 31 dead, revising down an earlier tally of 38 killed.
Ukrainian Deputy Foreign Minister Danylo Lubkivsky told the BBC he regretted the loss of life but insisted Russia was behind the violence.
“The situation remains under control. But the security situation is threatened by Russian special agents,” he said.
“That’s why we are requesting and demanding Russian authorities to stop their efforts that can undermine regional security and stability.”
Meanwhile, Russia’s foreign ministry said Moscow was “outraged” by events in Odessa and denounced Kiev’s “irresponsibility”.