An electrician has been hailed a hero after rescuing dozens of people from the wreckage of the Russian train derailed in a terror attack.

Sergei Vasilyev, in his mid-fifties, was the only person on duty at an electrical substation near the disaster. He immediately rushed to the scene, in forests and swamps a six-hour drive from Moscow.

Details of his heroic actions only emerged yesterday, 48 hours after the crash, which claimed at least 25 lives.

With the help of two passengers, he brought about 50 people from the mangled train into his substation, his superiors said.

“He simply carried people out of the epicentre of the nightmare,” said Yakov Zhelyabin, head of power supply for Oktyabrskaya Railroad, the unit of Russia’s state railroad company that runs Moscow-Saint Petersburg trains.

Access to the site was limited because of poor roads and the first ambulances arrived only an hour and a half after the disaster, said Vasilyev’s immediate supervisor, Oleg Panfilov.

Until they arrived the shocked, bleeding passengers were left to their own devices, Panfilov said.

Vasilyev brought the injured into the warm premises of his substation and laid them on blankets on the floor.

Three passengers died in the substation. “There was no one here” to help, Panfilov said, adding: “But he didn’t lose heart.”

Despite his heroic actions, Vasilyev insisted he did nothing special.

“I just gave people some help,” he said. Asked how many he helped, Vasilyev said: “I have not counted.”

His bosses, though, would not let him be so modest. Zhelyabin said: “He’s a hero of our time.”

He said rescue efforts were hindered by the fact that there were not enough ambulances.

Officials say 25 people died and 104 were injured in the disaster, though a final death toll has not yet been released.

“When we arrived everything here was soaked in blood,” Zhelyabin said of the substation. “The smell of blood hung over here.”

Meanwhile Russian police were yesterday hunting for the bombers behind the attack. It remained unclear why the attackers had struck the Nevsky Express, a train popular with well-off Russians and foreign tourists, as it ran from Moscow to Saint Petersburg late on Friday.

The chief of Russia’s FSB security service had said earlier that the blast that derailed the train was caused by an improvised explosive device with the force of 7kg of TNT.

There has been no immediate credible claim of responsibility for the attack.