A powerful blast that set off a fire at a shopping center in the Armenian capital Yerevan killed six people and injured more than 60 others, officials announced on Monday, as rescuers combed through wreckage searching for victims.

Officials initially said two people were killed, but the death toll has kept climbing as rescuers look for victims amid slabs of concrete and twisted metal. Another 18 people remain missing and at least 61 people were injured.

The Armenian Ministry of Emergency Situations earlier said four women and one man died, over 60 were injured and 19 were missing after Sunday's blast at the Surmalu wholesale market.

Search and rescue operations were carried out overnight, it said, with 10 survivors and one body pulled from the rubble.

The explosion caused a fire and led to the collapse of a building.

The cause has not yet been established, but local news reports, citing witnesses, said the explosion went off at a place that stored fireworks.

Photos and videos posted on social media showed a thick column of black smoke over the market and what appeared to be a series of detonations can be heard.

Prosecutors meanwhile launched a probe into violations "on stocking inflammable goods," breaches in fire safety standards and the death of people "due to negligence."

In all, 200 firefighters and medical workers were sent to the scene, as well as fire engines and construction site equipment.

Rescue workers used a digger to clear away rubble, an Agence France-Presse (AFP) journalist at the scene reported earlier.

The disaster comes as the country of 3 million people is still recovering from a 2020 war with Azerbaijan, which ended in a heavy defeat and sparked a political crisis.