The death toll from a powerful explosion in a south Ukrainian apartment block has risen to 19, with 15 others still missing, media reports said Thursday.

The blast shattered a five-storey building in the Black Sea resort of Yevpatoria on the Crimean peninsula, according to Ukraine's Channel 5 television.

The cause of the blast, which destroyed 35 apartments Wednesday night, has not yet been established, said Emergency Situations Ministry spokesman Igor Krol.

However, it was "quite possible that there had been containers of oxygen or acetylene stored in the building," he said.

Some 550 rescuers combing through the rubble in search of survivors had rescued 21 people so far, Krol added.

About 50 residents were evacuated from the neighborhood following the blast, he said.

"As I was walking by, I heard a bang, and then I saw this building crumble," an eye-witness told Channel 5.

President Viktor Yushchenko and Prime Minister Yulia Tymoshenko have rushed to the scene to oversee the rescue effort, according to their respective press services.

Gas blasts in old and dilapidated apartment buildings are not uncommon in Ukraine, particularly in winter when residents use more heating. Fifteen people were killed in a similar blast in October 2007 in Ukraine's central city of Dnipropetrovsk.

(Xinhua News Agency December 25, 2008)