Pope Francis offered condolences and prayers, along with calls for worker safety, after a factory collapsed and killed more than 350 people in Bangladesh.

"I express my solidarity and deepest sympathy to the families mourning their loved ones," he said at Saint Peter's Square on April 28.

In his Regina Caeli address, the Holy Father offered prayers "for the many victims" of the tragedy.

On April 24, an eight-story building collapsed in the Rana Plaza complex in Savar, just north of Dhaka, killing at least 352 people.

Around 30 survivors were found yesterday, but police say nearly 1,000 are still missing, trapped under the building's remains.

Rescue teams were still searching for survivors on the night of April 27, using electric drills, shovels and their bare hands.

Police have detained two of the factory's owners as well as two engineers involved in issuing the building's permits.

The building collapsed just a day after warnings had been given saying it was unsafe. A petition has been launched calling for compensation to be given the victims and their families.

A demonstration outside a Primark retail store was held in London after it was revealed that the company had used a floor of the building that collapsed.

Pope Francis appealed in his address for "the dignity and safety of the worker" to always be respected.