The announcement, formally ending more than 30 years of separatist rule, came after Azerbaijan regained control of the breakaway enclave in a swift attack a week ago.
The cause of the Monday blast in the breakaway region of Azerbaijan, where thousands have been fleeing for Armenia, was still unclear. Hundreds were wounded.
Nearly 400 people crossed the border from the breakaway region of Nagorno-Karabakh on Sunday, days after a military offensive returned the ethnic Armenian enclave to Azerbaijan’s control.