Five of the wounded were hospitalised for treatment, including one in serious condition.

Slim probability

Rescuers, who had worked through the night, were now clearing away debris from what had been the basement and the probability of finding more survivors or more victims were slim, Mazilin said.

It is not known how many people were in the building when the explosion went off on Thursday.

A further 21 people have been rescued from the rubble, an official from the ministry for emergency situations said.

Viktor Yushchenko, Ukraine's president, and Yulia Tymnoshenko, the prime minister, laid aside their differences on Thursday to visit the accident site.

Ukrainian television showed a grim-faced Yushchenko driving from the shattered building with a somber Tymoshenko at his side.

It was the first time in months, aside from state ceremonies, the pair had been seen in public together.

Explosive materials

Two sections of the apartment building, constructed in 1965 and containing around 35 flats, were destroyed in the explosion.

According to Mazilin, rescue efforts were coming to an end and are expected to be complete about mid-day.

The possibility of more oxygen cylinders still buried slowed the search effort [AFP]
The government has said that the accident, which completely destroyed two sections of the apartment block, was likely caused by an explosion of oxygen or acetylene cylinders stored in the building's basement.

Residents had previously complained to city authorities of an illicit repair shop operating in the basement, the Sehodnia newspaper reported.

The possibility of more oxygen cylinders still buried under the rubble was slowing the search effort.

The potential of another oxygen detonation prevented the use of welding torches to cut through reinforced concrete slabs in the debris, Sehodnia said.

Explosions in ageing and poorly maintained Soviet-era apartment buildings, usually caused by gas, are not unusual in Ukraine and the former Soviet Union.