At least 31 people are believed to have been killed in an explosion at Moscow's Domodedovo airport.
Domodedovo is the busiest of the Russian capital's three commercial airports and reports have suggested a suicide bomber was responsible.
Russian news agencies cited unspecified sources as saying the blast occurred inside the airport's international arrivals hall.
The Russian state news agency has said around 130 people are thought to have been injured.
Local media reported smoke billowing out of the baggage claim area and people were seen running out of the emergency exits.
Airport security has confirmed that shrapnel, screws and metal balls were found at the site of the blast.
Travel writer Simon Calder told Sky News the airport is seen as the "shiny new face of Moscow" and many big airlines, including British Airways, use it.

The airport is around 22km from the capital
Security has been stepped up across Moscow following the deadly explosion.
Moscow suffered its worst attack in six years in March 2010 when two female suicide bombers from Russia's volatile Dagestan region set off explosives in the metro, killing 40 people.
Russia is battling an Islamist insurgency in the Caucasus and deadly attacks on government and police officials in Dagestan as well as neighbouring Chechnya and Ingushetia are an almost daily occurrence.
In 2004, two suicide bombers were able to board planes at Domodedovo by buying tickets illegally from airport personnel.
The bombers blew themselves up in mid-air, killing all 90 people aboard the two flights.