KIEV (Reuters) - Eight miners were killed in a methane gas explosion in a coal mine in western Ukraine's Lviv region on Thursday and 20 other workers were still unaccounted for, Ukrainian emergencies service said in an online statement.

It said 34 miners were at a depth of 550 meters when the explosion ripped through the mine at 12.46 local time (17.46 ET).

(Reporting by Pavel Polityuk; Editing by Alessandra Prentice and Jon Boyle)