Moscow's Domodedovo International Airport (Creative Commons).

Russian President Dmitry Medvedev ordered more security at all three of Moscow's airports after authorities say a suicide bomber carrying a suitcase set off an explosion Monday in Domodedevo International Airport, killing 35 and wounding 180.

"This is a terrorist act, this is grief, this is a tragedy," Medvedev said.

The international arrivals hall of Moscow's busiest airport filled with smoke after the explosion, leaving hundreds of foreign travelers leaving customs trapped in the rubble and shrapnel. Russian officials determined the blast happened in an area that was not heavily guarded near the baggage claim area, near several eating establishments.

A Russian investigator said officials were attempting to identify the suicide bomber, but no progress had been made as of Saturday morning. The Interfax news agency, however, reported that the head of the bomber had been found.

According to law enforcement, airport security was aware that there was a plot against Domodedevo, but they were unable to locate the three men they were looking for. Russian counterterrorism officials blamed insufficient airport security for the attack.

"Security measures in the Domodedovo airport were insufficient, otherwise the terrorist attack would never have taken place," Nikolai Sintsov, a spokesperson for Russia's anti-terrorism committee told Russian TV.