Ukraine is observing a day of mourning on Sunday for 37 miners killed in accidents at two coal pits in the country's industrial east.

Ukrainian President Viktor Yanukovich ordered state flags to be lowered to half mast, while relatives held the first funerals for the victims of Friday's twin disasters, the country's deadliest since 2007.

Authorities also recovered the bodies of the last missing miners at the two sites. In one accident, a suspected methane gas explosion shook a mine in the Lugansk region, killing 26 workers. In the other accident, 11 miners were killed when their elevator collapsed at a pit in the neighboring Donetsk region.

Mr. Yanukovich has called for a government commission to investigate the accidents.

Ukraine's coal mines are among the world's most dangerous because of outdated equipment and disregard for safety regulations.