Russian counter-terrorism agents have carried out a raid on a group planning a terrorist act in Moscow killing two suspects, officials say.
The National Anti-Terrorism Committee said the group was located in a house in the town of Orekhovo-Zuyevo, east of the capital.
A third suspect was held in the raid. One agent was slightly hurt.
The suspects are said to be Russian citizens who had undergone training in the Afghanistan-Pakistan region.
The committee statement said: "During an active special operation the bandits were cut off, but when they were called on to surrender they opened fire."
"Thanks to the decisive actions of the law-enforcement agents, an attempt to carry out a terrorist act in the capital was thwarted."
Unnamed official sources told Russian news agencies the group's target was a mass event in central Moscow, but further details were being withheld while the plot was investigated.
All three were Muslims and had been under observation for a month, another source told Interfax news agency, adding that they had been trained in North Waziristan, a mountainous region of north-west Pakistan and a stronghold of Taliban and al-Qaeda-linked militants.
The authorities are investigating possible links between the suspects and the militant Islamic Movement of Uzbekistan, the source said.