At least 20 people are believed to have been killed in an explosion at Moscow's Domodedovo airport Skynews reports. 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.

Around 130 people are thought to have been injured.

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.

He said this attack will worry the Western airlines which have moved to Domodedova which has become Russia's main international airport.

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.