Quetta Division Commissioner Hamza Shafqaat said it was a suicide attack and 24 people were killed in the blast.
The suicide bomber had entered the station with luggage, the commissioner said, adding that was difficult to stop a person coming with an intention to carry out a suicide attack.
The
The suicide bombing comes a week after a blast near a girl's school and a hospital in Balochistan's Mastung district killed eight people, including five children.
Earlier, SSP Operations Muhammad Baloch had also said that initial findings point to a possible suicide bombing. While confirming the death of 21 people, he had warned the number of victims could rise.
Rescue and law enforcement teams responded immediately, securing the area and transporting the injured and deceased to Civil Hospital Quetta, according to the provincial government spokesperson Shahid Rind.
An emergency was declared at the hospital where additional medical staff was summoned to deal with the injured, where officials said that 46 injured had been shifted so far.
The blast, which also damaged the platform's roof, was heard far and wide in various areas of the city.
Balochistan Chief Minister Sarfraz Bugti condemned the attack, terming it as "a horrific act targeting innocent civilians", and ordered an immediate investigation.
He said that terrorists are increasingly aiming civilians, labourers, women, and children, and vowed that those responsible would be pursued relentlessly.
Pakistan, particularly the Balochistan and Khyber Pakhtunkhwa provinces, has seen a sharp uptick in terrorism-related incidents over the past year.
According to the Centre for Research and Security Studies (CRSS), the third quarter of the ongoing year witnessed a 90 per cent surge in violence in Pakistan, the Geo News reported.
With a total of 722 people being killed, including civilians, security personnel, and outlaws, while 615 others were wounded in as many as 328 incidents recorded during the period under review, 97% of these fatalities occurred in Balochistan and Khyber Pakhtunkhwa provinces.
Over 92% of these incidents of terror attacks and security forces' operations were recorded in the same provinces.
The total fatalities from three quarters of this year have now surpassed the total fatalities recorded for the entire 2023; the number of fatalities rose to at least 1534 in the first three quarters compared to 1523 in 2023, the report said.