President Dmitry Medvedev has called terror the most serious threat to Russia and vowed to "liquidate" the militants behind the Moscow airport bomb blast that killed 35 people.

"Terrorism remains the main security threat to our state," Medvedev said after observing a moment of silence during which he could be seen choking back tears.

"We have to do everything to make sure that the bandits who committed this crime are identified, exposed and brought to court, and the nests of these bandits -- or whatever they may be called -- must be liquidated," Medvedev said in televised remarks.

Medvedev also instructed his government to probe whether those responsible for ensuring the country's transportation security had properly performed their jobs.

He said the prosecutor general's office and Russia's investigative committee needed to probe "the criminal responsibility" of those blamed for allowing the suspected suicide bomber to walk into Domodedovo airport undetected.