A natural gas explosion destroyed a section of a block of flats in Dnipropetrovsk on Saturday morning. Thirteen people were killed, 17 people were being treated in hospital, the Emergency ministry said. Rescuers were still seeking more than 20 people who could have been caught inside the building, home to about 400 people.

A team of around 100 rescue workers with sniffer dogs searched for survivors after emergency services evacuated residents from the remaining part of the block.

According to the President`s press-office, President Victor Yushchenko immediately ordered Prime Minister Viktor Yanukovych to start an investigation into the causes of the tragedy and help its victims. He sent his condolences to those who were injured in the blast and to the families of those who were killed.

The president is following rescue and recovery efforts in Dnipropetrovsk.