MOSCOW, Sept 29 : The death toll from an explosion and fire at a fuel depot in Nagorno-Karabakh has risen to 170, Armenpress news agency reported on Friday citing local officials in the breakaway region. The blast occurred as thousands of ethnic Armenians fled the breakaway enclave after their fighters were defeated by Azerbaijan in a lightning military operation. The authorities have not given any explanation of the cause of the blast. The number of victims rose sharply from an earlier announcement by Karabakh authorities reporting 68 dead on Tuesday evening. Rescue work at the blast site continues. As of Friday morning, more than 84,700 of the 120,000 ethnic Armenians who call Nagorno-Karabakh home had already crossed into Armenia.