The former deputy governor of Zamfara state, Ibrahim Wakkala also sustained gunshot wounds from the attack on a train going to Kaduna state from Abuja.
The attack occurred around Kateri-Rijana area of Kaduna on Monday.
The train was said to have almost reached Rigasa, its final stop when gunmen opened fire on it.
Channels Television quoted Yusuf Idris, an aide of the former deputy governor, as saying Wakkala was returning from the APC national convention that was held on Saturday.
Idris said Wakkala was initially abducted by the gunmen but was rescued by the military and the Department of State Services (DSS).
He said it was during the rescue operation that Wakkala sustained a gunshot wound.
“He was initially abducted but was rescued by the DSS and military, it was during the process he sustained gunshot injury in the leg,” he said.
“He is very okay now, he is receiving treatment at the hospital in Kaduna state.”
The Nigeria Railway Corporation (NRC) has suspended its operations along Abuja-Kaduna route.