Ukrainians are holding a national day of mourning to remember the victims of an explosion that tore apart a block of flats two days ago.Up to 24 people are reported to have died. Around 20 are still thought to be missing, but officials do not know exactly how many people were in the building at the time of the blast on Christmas Eve. Ukraine’s president and prime minister put aside their political arguments, and arrived at the scene together. President Viktor Yushchenko said: “This is a tragedy which has brought us all here. I want to say that all those who suffered from it will get new housing before the New Year.” Prime Minister Yulia Tymoshenko expressed her condolences to all those who lost relatives, and promised the equivalent of 9,000 euros in government aid for suffering families. The apartment block was in the Black Sea resort of Yevpatoria. One witness said 35 flats were completely destroyed. The Prime Minister said preliminary investigations seemed to lay the blame on gas bottles which were being illegally kept in a basement workshop. Twenty one residents were pulled out alive, but rescuers hold out little hope for anyone else still under the rubble.