At least 30 people have been killed after two express trains collided in southern Pakistan.

Rescuers and villagers have been working to pull injured people and bodies from the wreckage, and as many as 20 passengers are feared to be trapped.

Railway officials said about 1,100 people were on board the two trains at the time of the crash in Ghotki, a district in Sindh province.

The Millat Express train had derailed, with the Sir Syed Express hitting it soon afterwards.

“Right now the challenge for us is to quickly rescue those passengers who are still trapped in the wreckage,” deputy commissioner Usman Abdullah said.

Reports on Pakistani television have suggested that heavy machinery to help with the rescue effort took about four hours to arrive.

Dozens of others are feared to have been injured, and some are in a critical condition.

Train accidents are common in the country owing to a poorly maintained signal system and ageing tracks.