President Viktor Yanukovich ordered a national day of mourning on Sunday as the number of dead in two separate Ukrainian coal mine accidents rose to 32.
An explosion in a mine in the Luhansk region early on Friday killed at least 24 people and injured two, according to an updated report on the Emergencies Ministry website. Two miners remained missing.
Also early on Friday, eight miners died and four were injured at a state-owned mine in the Donetsk region when a piece of heavy machinery collapsed. Three people were missing.
The Luhansk accident was the deadliest in a Ukrainian coal mine since 2007, raising concerns over the industry's safety standards. The blast-hit mine is owned by Ukraine's richest man, steel tycoon Rinat Akhmetov.
Yanukovich ordered his government on Friday to investigate the accidents and develop a new programme to ensure miners' safety. He published a decree on Saturday ordering state flags to fly at half mast on Sunday.
The Emergencies Ministry said the cause of both accidents had yet to be established.