No fewer than nine people were killed and about 20 people are trapped in northeastern Mexico after the roof of a church collapsed during a service on Sunday, Oct. 1.

Local media said 49 people were taken to hospital, after the roof of Ciudad Madero's Santa Cruz church fell in.

Police in the coastal state of Tamaulipas said around 100 people were at a mass at the time of the collapse.

A number of children are believed to be amongst those trapped and rescue efforts are ongoing.

Local media reported that at least 20 people were still missing under the rubble and that a baptism was being celebrated when the ceiling collapsed.

A government statement said the incident occurred in the early afternoon.

In images broadcast on Milenio Television, dozens of people can be seen trying to hold up part of the collapsed structure with poles while others make their way through the wreckage in search of survivors.

“We are experiencing a very difficult moment… the roof of a church has collapsed during the celebration of the Eucharist,” the bishop of the local diocese Jose Armando Alvarez said in a video posted to social media.

Local journalist Franc Contreras told the BBC World Service's Newsday programme that the collapse happened at a key moment in the church service.

"The church was packed with about a hundred people, and people were lined up to take the communion - of course that's sort of the climax of the Catholic mass - and that's when the roof came down on top of them; bricks, concrete, and of course steel support structures coming down on top of the people," he said.

Authorities were said to be requesting silence from those gathered at the scene so that they could hear if anyone trapped inside was calling for help.