Armenian media outlets reported that twenty people were killed and 290 others were injured when a powerful blast ripped through Karabakh on Monday evening.

The explosion took place at a fuel storage facility near Khankendi (Stepanakert), where Azerbaijan launched a counterterrorism operation last week against separatists. The cause of the explosion was unclear, and it was reported that the area was crowded as people lined up to get fuel for their cars before leaving the region. Some victims were airlifted out of the region for medical treatment.

Azerbaijan suspended its counterterrorism measures in Karabakh on Sept. 13, a day after they were launched to disarm Armenian forces in the region and uphold the 2020 trilateral peace agreement.

Baku announced that medical equipment was sent to Karabakh to address the needs of people injured in the explosion. Azerbaijan already sent humanitarian aid to the region after the counterterrorism operations, and another convoy for assistance containing food and other materials was also dispatched to Khankendi on Tuesday.