New Delhi, Aug. 2 -- MOSCOW - The security guard at Balzi Rossi died trying to stop the woman at the door. She was carrying an explosive device, Russian authorities said Saturday, and when the bomb detonated on Kudrinskaya Square in central Moscow that evening, the guard was among three people killed. Twenty-one others were wounded in what Russia's National Anti-Terrorism Committee confirmed was a deliberate attack using an improvised explosive device.

55 p.m. Moscow time on August 1, at a restaurant occupying the ground floor of one of the seven Stalinist high-rises that ring Moscow's historic center. Kudrinskaya Square's tower, one of Stalin's Gothic skyscrapers completed in the early 1950s, houses apartments, offices, and the restaura...