A rescue operation is underway to help people get out of the wrecked train and recover the victims' bodies, the broadcaster said.
Police Chief Umer Salamat said the train was traveling from the eastern city of Lahore to southwestern Balochistan Province when the accident occurred at the Walhar Railway Station near Rahim Yar Khan in the early morning hours of July 11.
Twenty people were killed in the train crash and 74 were wounded, with some in critical condition, according to Javed Ahmed, a physician treating the wounded.More news: Couple claims clinic implanted their embryo in wrong woman
The freight train was standing on the loop line when the speeding passenger train instead of running on the mainline went on the wrong track.
In a social media post, PM Imran Khan said, "Saddened to learn of train accident in Sadiqabad".
The engine of the Akbar Express was completely destroyed in the accident while three compartments were also damaged, police said.More news: Study finds possible link between sugary drinks and cancer
Train accidents and periodic derailments in Pakistan are often the results of the country's aging railway network.
Jamil added that heavy machinery was being used to remove passengers who were stuck in the train, adding that they were being provided with food and water.
Khan said on his official Twitter account that he has asked the railways minister to take emergency steps to counter decades of neglect of railways infrastructure and ensure safety standards.More news: Labour should automatically expel anti-Semites, says Sir Keir Starmer
He said a state of emergency has been declared in Sheikh Zayed Hospital and Tehsil Headquarters Hospital, while a control room has also been set up for better coordination. Sadiqabad: 10 Killed, 35 Injured in Trains Collision.