Officials said the Akbar Bugti Express travelling from Lahore to Quetta collided with a stationary freight train at the Walhar Railway Station in Sadiqabad Tehsil of Punjab province, reported Geo News.

The freight train was standing on the loop line when the other train, which was running on the wrong track, collided with it.

According to Geo News, three to four bogies of the passenger train derailed while the engine of the passenger train was completely destroyed. 

Eyewitness to the train accident told the news channel that the accident occurred at 4am when most of the passengers were sleeping. 

Resuce team later reached the spot and started the rescue process.

Sources at the Jinnah and Shaikh Zayed hospitals told Geo News that three people injured in the accident succumbed to their wounds during treatment, raising the death toll to 21.

Speaking to Geo News, Railways Minister Sheikh Rasheed Ahmed expressed deep grief and sorrow over the loss of lives in the accident and said the accident occurred due to negligence. 

Pakistan PM Imran Khan also mourned the loss of lives in the incident.

"Saddened to learn of train accident in Sadiqabad. My condolences to the victims families and prayers for the speedy recovery of the injured. Have asked Railways Minister to take emergency steps to counter decades of neglect of railway infrastructure & ensure safety standards," Khan tweeted.