Ukrainians are observing a day of mourning for the 27 people killed in a suspected gas explosion that destroyed sections of a five-story apartment building Wednesday.

Rescuers pulled out 21 survivors from the ruins before authorities began winding down their search in the Crimean Peninsula resort of Yevpatoria.

Officials say they found a family of five among the dead.

Investigators believe oxygen canisters stored in the basement exploded.

President Viktor Yushchenko and Prime Minister Yulia Tymoshenko put aside their political bickering and traveled together to the scene of the disaster.

Russian President Dmitri Medvedev offered to send personnel from Russia's Black Sea fleet to help in the search for survivors.

Some information for this report was provided by AFP, AP and Reuters.