Eighteen people are dead and dozens more are feared missing after the collapse of the roof of a supermarket in the Latvian capital Riga.

Rescue efforts continued through the night, while Prime Minister Valdis Dombrovskis has announced that a criminal investigation in violating construction norms has begun.

Speaking for Latvian TV, Interior Minister Rihards Kozlovskis has stressed that "it was clear to him that there has been a problem with fulfilment of construction requirements."

At least 35 people have sustained injuries, according to the latest update.

Three of those killed were emergency workers, who were helping people trapped, when more of the roof came down – 20 minutes after the initial collapse. The cause of the collapse is unclear although reports, quoted by the BBC, say a garden was being constructed on the roof at the time and the weight of the soil could be a contributing factor.

The initial collapse happened just before 6 pm local time Thursday, when the store was busy with customers. In addition to the roof, walls and windows of the single-story concrete and glass building also crumbled.

TV footage showed rescue workers using mechanical cutters to clear debris from. Cranes were brought in to remove slabs of concrete. More than 60 soldiers are helping the rescue effort, the army, cited by The BBC, said on its official Twitter feed.

According to witnesses, customers tried to run out, but the supermarket's electronic doors closed, trapping them inside.

The supermarket, which opened in 2011, is part of the Maxima retail chain.

We need your support so Novinite.com can keep delivering news and information about Bulgaria! Thank you!