On Monday evening, the gang mined the track, causing the train carrying 970 passengers to come to a halt.
According to one passenger, gunmen surrounded the carriages and opened fire.
An unknown number of passengers were kidnapped from the train, which was regarded as the safest mode of transportation between the cities.
Kidnapping for ransom has become all too common in Nigeria.
The Abuja-Kaduna highway is one of the most dangerous in the country, with kidnappers ambushing vehicles at several points along the route.
This has pushed many people to avoid the 150km (93-mile) road trip in recent years, instead opting for the rail link, which opened in 2016. It is more expensive, but it is considered safer because the trains are guarded by armed guards.
According to the BBC’s Chris Ewokor in Abuja, this is the second time the rail line between the cities has been targeted in the last six months, but it is by far the most serious.
The BBC Hausa service reports that 22 people were injured in the attack on Monday evening and are being treated at a military hospital in Kaduna.
One woman volunteering in a hospital in Kaduna told the BBC’s Focus on Africa radio programme that the first-hand accounts she had heard were “scary” and “traumatizing.”
A railway worker told her that he had escaped the kidnappers by fleeing as they led him and “25 people into the forest” on foot.
Another person stated that when she was shot, “the bullet went straight through her.”
Nigerian Railway Corporation (NRC) operations along the route have been halted.
The governor of Kaduna state has also condemned the attack, calling it a “terrorist” incident and expressing condolences to the victims’ families.
Millions of people in northwestern states use the rail line to travel to Abuja and further south.
Authorities in Kaduna state say they are working with the NRC to determine where all of the passengers are and who is missing.
Despite military bombardment of their hideouts, armed gangs carrying out killings and kidnappings for ransom have continued to unleash violence, particularly in northern Nigeria.
They attacked Kaduna’s international airport just last Saturday.
Source: BBC
