A demonstration was held at the Ministry of Transportation in Abuja on Monday morning by the relatives of victims still in captivity.
The protest was triggered by footage released Sunday by the kidnappers, who were shown mercilessly flogging the captives. The kidnappers also threatened to kill some of the victims and sell the rest if the government did not respond to their demands.
They also threatened to abduct Nigerian President Muhammadu Buhari and Kaduna state Governor Nasir El-Rufai.
It is not clear what the terrorists’ demands are, but the video triggered criticism of the government's inability to rescue the victims.
On Sunday, the president's spokesperson, Garba Shehu, called the terrorists’ threats "propaganda" and said security and defense forces "have their plans and ways of doing things."
Shehu was not immediately available for further comment, but security analyst Senator Iroegbu said the terrorists cannot possibly kidnap the president. But he warned that the threats must be taken seriously.
"They're trying to show that they're more emboldened and there's nothing the commander in chief can do. They could smell weakness, that this government is weak. The fear is that citizens are more vulnerable."
Nine people were killed, and scores kidnapped on the Abuja-Kaduna train the night of March 28 after armed men bombed the tracks and derailed the moving train.
Experts blamed the attack on an unprecedented alliance between jihadists and criminal gangs.
In the recent video, one of the terrorists claimed to have been freed from the Kuje prison in Abuja after a jail break on July 5.
The claim corroborates claims that bandits and terror groups were working hand in hand, says Iroegbu.
"Terrorists can use banditry as a means to obtain money to advance their cause. Bandits can also use terrorism to obtain whatever they're looking for, so there's a mix already. The linkage between terrorism and banditry that is going on, the terrorists have seen a loophole there and married the two together.
Protesting relatives say they will not relent until authorities free their loved ones from their captors.
Temitope Kabir's husband is among those held.
"We're tired of waiting. We don't want a situation where these people will carry out their threats. We need the government to do something, and they should do it now. We're ready to be here for as many days as we can under rain, under sun.
Experts and families say Nigerian authorities have shown weak political will to secure the release of the victims. But authorities say they're trying to tactically handle the issue without losing innocent civilians to a gun battle with the terrorists.
This month, the Islamic State West Africa Province (ISWAP) claimed responsibility for a jail break that freed hundreds of inmates from Kuje prison, including high-profile terrorists.
Authorities have been searching for missing inmates. Also this month, Buhari’s advance convoy was ambushed in his hometown in Daura in northwest Katsina state. The president was not in the convoy.