A bomb attack at Moscow's Domodedovo airport has killed at least 35 people and injured more than 100 - many of them critically, officials say.
Investigators say the explosion, which happened in the arrivals hall, was caused by a suicide bomber.
President Dmitry Medvedev vowed that those behind the attack would be tracked down and punished.
He ordered increased security across Russia's capital, its airports and other transport hubs.
Mr Medvedev also called an emergency meeting with officials and also postponed his planned departure for this week's World Economic Forum at Davos.
The airport - the busiest serving Russia's capital - is 40km (25 miles) south-east of the city centre.
Footage from mobile phones showed the arrivals area filled with smoke, with bodies strewn across the floor, shortly after the attack around 1630 (1330 GMT).