Russian security forces shot dead two suspected terrorists carrying explosives in the city of Nizhny Novgorod, Russian news agencies reported.
An explosion during the operation injured two special police officers, while a third suspect was captured alive, reports citing law enforcement sources said.
"Law enforcement officers stopped a car, two suspects resisted arrest and were liquidated on the spot. Explosives were found in the car," TASS state news agency quoted a source as saying.
The special operation is reportedly taking place in a residential area of Nizhny Novgorod, an industrial city on the banks of the Volga River, around 400 kilometres (250 miles) east of Moscow.
A law enforcement source told RIA Novosti: "They have shot dead two [people] suspected of terrorism. They were driving in a Daewoo Nexia car. Now FSB (security force) officers are working at the scene."
Local media posted photographs from social networking sites apparently showing two bodies lying on the ground close to a car with doors open, as vehicles and security officers block the nearby road in a suburb called Tsvety.
A robotic device can also be seen in the photograph. TASS reported that the anti-mine robot was used to neutralise an explosive device in the car.
A law enforcement source quoted by TASS named those killed as "members of illegal armed groups," a term also used by officials to describe Islamist insurgents in the North Caucasus.
There was no immediate official confirmation of the reports.
