An explosive device went off under a train in the Russian North Caucasus Republic of Dagestan on Monday, a local emergencies spokesman said.
Rail monopoly Russian Railways said no one was injured in the explosion.
The train, which was en route West Siberia's Tyumen to Azerbaijan's capital, Baku, did not derail, the emergencies official said.
The attack comes days after a bomb blast caused the derailment of the Nevsky Express from Moscow to St. Petersburg. Twenty-five people died in Friday's accident, with six still unaccounted for and 90 still in hospitals, 21 in critical condition.
Violence is common in the southern Russian republic, which neighbors Chechnya, with officials often targeted. A local police spokesman said that the head of Dagestan's Magaramkent District, Abrek Gadzhiyev, was killed on Monday morning.
Gadzhiyev's car came under fire in Makhachkala, Dagestan's capital.
"Gadzhiyev died of wounds, and his injured driver has been hospitalized," the police official said. The driver underwent surgery and remains in serious condition.
MAKHACHKALA, November 30 (RIA Novosti)