ABUJA, Nigeria—Gunmen attacked a train near Nigeria’s capital on Monday night with explosives and gunfire, killing an unspecified number of the nearly 1,000 passengers on board, authorities and survivors told The Associated Press on Tuesday. The attackers used explosives to first blow up the rail track before opening fire on the train near Abuja in northwest Nigeria, according to Fidet Okhiria, chief executive of the state-owned Nigerian Railway Corporation. Many people are also feared to have been abducted during the “unprecedented” attack, he said. Authorities could not immediately confirm the number of passengers on the train but local media reported that nearly 1,000 were on board. “There were casualties but we have not been able to confirm the number,” said Okhiria, calling the attack a major setback. It is the latest in a series of other train attacks. Abdulwadud Ahmad, a survivor, said he knew of nine passengers killed including …