Pakistani officials say two trains collided in southern Pakistan Monday, killing and injuring dozens of people.

Authorities say the Millat Express, a passenger train operated daily by Pakistan Railways, derailed and slid onto the track of the oncoming Sir Syed Express near Dharki, a city in the Ghotki District of upper Sindh.

A police official says that more than 30 people were killed in the accident and at least 50 injured. The death toll is expected to rise.

Media reports say emergency workers are having trouble rescuing people from the overturned train cars.

Ghotki Deputy Commissioner Usman Abdullah told Geo News the rescue operation is “a challenging task” and that “It will take time” using heavy machinery to free people who remain trapped.