Ukraine is in mourning for the 27 people killed in an apartment block explosion in the small Crimean town of Yevpatoria on Wednesday.

Twenty-one people were rescued from the wreckage, but the cause of the tragedy remains unknown.

Flags are being flown at half-mast throughout the country. TV and radio schedules have undergone appropriate changes, with all entertainment programmes cancelled.

The blast ripped apart the five-storey block at around 10pm on Wednesday in the Crimean city of Yevpatoria.

It's believed oxygen tanks exploded in the basement of the building. Around 35 dwellings were destroyed.

Medical and psychological help is being provided to the victims and their families. Local authorities have been ordered to provide residents of the block with temporary accommodation.

A special governmental commission headed by Ukraine’s First Deputy Prime Minister Aleksandr Turchinov has been sent to Yevpatoria.

President Viktor Yushchenko and Prime Minister Yulia Timoshenko also flew to the city on Thursday.