ISLAMABAD -- At least 20 people were killed and 53 others injured on Saturday morning in a blast at a railway station in Pakistan's southwest Balochistan province, chief executive officer of Pakistan Railways said.

The attack happened at about 8:20 am local time (GMT 0320) at Platform No? 1 of the railway station in the provincial capital city of Quetta where the train Jaffar Express was ready to depart, the railways said in a statement.

Talking to Xinhua on condition of anonymity, military sources from Quetta said that the target of the attack were soldiers leaving for their homes in other provinces after completing a training course in Quetta.

The sources said that a suicide bomber blew up his explosive jacket in a crowd of over 100 people, including soldiers, railways police, and civilian passengers.

Railway officials said Jaffar Express remained safe during the attack and has been rescheduled.

Muhammad Zeeshan, manager of operations of the rescue department of the Edhi Foundation in Quetta, told Xinhua that the injured people included two railway police officials, and a woman was also among the killed.

He said that both the killed and injured included troops as well as civilians who were getting onboard the train whose final destination was Peshawar city of the country's northwest Khyber Pakhtunkhwa province.

The proscribed group Balochistan Liberation Army claimed responsibility for the attack in a press release shared with media and on social media platforms.

Police, security forces, and rescue teams rushed to the site and shifted the bodies and injured to hospital.

Pakistan's Prime Minister Shehbaz Sharif condemned the attack and directed the hospital administration to provide the best possible medical treatment to the injured people.