A witness to the massive explosion that killed at least 35 people at Moscow's busiest airport Monday says he saw a man carrying a flaming suitcase seconds before the blast.
Artyom Zhilenkov, a 35-year-old driver, told The Associated Press he was just a few yards away from the explosion and saw a man who may have been the bomber.
"I saw the suitcase, the suitcase was on fire. So, either the man blew up something, or something went off on the man's body, or the suitcase went off." said Zhilenkov, whose clothes were soaked in blood.
"The guy standing next to me was torn to pieces," he added.
Russian officials said the blast killed 35 people and wounded 180.
"From the preliminary information we have it was a terror attack," President Dmitry Medvedev told officials.
Russia's Interfax news agency reported that a head found at the site appears to belong to the bomber.
"We found the head of a man of Arab appearance, aged 30-35. It seems he detonated the explosive device," said the source.
Amateur video posted on YouTube showed the international arrivals terminal at Domodedovo Airport engulfed by smoke and splattered with body parts after the mid-afternoon terror attack sprayed shrapnel, screws and ball bearings at passengers and workers. Hundreds of people were in the loosely guarded area at the time.
Medvedev said the explosion demonstrated that security regulations had been breached and ordered Moscow police to beef up security at Moscow's two other commercial airports and other key transport facilities, including the subway system, the target of past terror attacks.
He also postponed his planned Tuesday departure for the World Economic Forum in Davos, Switzerland, where he was to give the opening address on Wednesday.
Although there have been repeated attacks on the Moscow subway and on Russian trains -- most blamed on Chechen militants -- the bombing Monday was the first involving a Russian airport since 2004.
Sergei Lavochkin, who was waiting in the arrivals hall for a friend to arrive from Cuba, said he saw emergency teams carrying bloodied people out of the terminal.
"I heard a loud bang, saw plastic panels falling down from the ceiling and heard people screaming. Then people started running away," Lavochkin told Rossiya 24 television.
Mark Green, a British Airways passenger who had just arrived at the airport, told BBC television he heard the huge explosion as he was leaving the terminal.
"Literally, it shook you," he said. "As we were putting the bags in the car a lot of alarms ... were going off and people started flowing out of the terminal, some of whom were covered in blood."
"One gentleman had a pair of jeans on that was ripped and his thigh from his groin to his knee was covered in blood," he added.
Green said thousands of people were in the terminal at the time of the blast.
In Washington, President Obama condemned the "outrageous act of terrorism against the Russian people" and offered assistance to Russian investigators.
Mass transit targets are preferred by several groups, including the Chechen rebels who have hit the Moscow subway in the past.
Domodedovo is generally regarded as Moscow's most up-to-date airport, but its security procedures have been called into question.
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.
Built in 1964, Domodedovo is located 26 miles southeast of the center of Moscow and is the largest of the three major airports that serve the Russian capital, serving more than 22 million people last year.
Currently 77 airlines offer regular flights to Domodedovo, serving 241 international and national routes, according to the airport's website.
The airport insists that security is one of its top priorities, claiming on its website that its "cutting-edge operations technology guarantees the safety of passengers' and guests' lives."
Twin blasts in the subway last March killed 39 people and wounded more than 60 people.
Chechen rebel leader Doku Umarov claimed responsibility for that attack, warning Russian leaders that "the war is coming to their cities."
In December 2009, Chechen rebels claimed responsibility for blowing up a high-speed train between Moscow and St. Petersburg, an attack that killed 26 people and injured scores.
NATO Secretary-General Anders Fogh Rasmussen said he was "deeply disturbed" by the reported terror attacks.
"I strongly condemn it," he said on Twitter. "NATO and Russia stand together in the fight against terrorism."
The Associated Press contributed to this report.