Dmitry Medvedev, the Russian president, has blamed a lapse in security at Moscow's biggest airport for a blast that left 35 people dead and more than 150 injured.
The explosion occurred on Monday afternoon when a suspected suicide bomber detonated a bomb in the arrivals hall near the baggage area at Domodedovo airport.
"What happened demonstrates that there were clear security breaches. Someone had to try very hard to carry or bring through such a vast amount of explosives," Medvedev said on Tuesday.
"Everyone linked to the company that makes decisions there, and the management of the airport itself, has to answer for everything. This is an act of terror. This is grief. This is a tragedy.
"Based on [the bomb's] location and other indirect evidence, this was a well-planned act of terror that aimed to kill as many people as possible."
Vladimir Putin, the prime minister, has vowed to avenge the attack, saying that "retribution is inevitable".
Security sources have suggested that a female suicide bomber from the North Caucasus could be behind the attack.
"The explosion occurred the moment the presumed female suicide bomber opened her bag," the state-run RIA Novosti agency quoted an unnamed security official as saying.
"The terrorist was accompanied by a man. He was standing beside her and [the blast] tore off his head."
Previous attacks in Russia have been blamed on so-called Black Widows from the predominantly Muslim North Caucasus, comprising women who volunteered for suicide bombings after losing their separatist fighter husbands.
A spokeswoman for Domodedovo said that all the security procedures had been followed correctly and that the airport was not to blame.
"We do not feel that we should be held accountable," Yelena Galanova told the Interfax news agency.
Sergei Martirosian, another airport spokesman, said that the inspection of people coming into the arrivals area, where the bomb went off, was the responsibility of transport police.
Neave Barker, Al Jazeera's correspondent in Moscow, said authorities may have known about the potential of the attack at least a week earlier, according to an unnamed security source.
"An anonymous tip-off was given to them telling them that the customs area of the airport could be specifically target. The big question is if that information was known why wasn't more done to stop that attack."
It is the second time in seven years that Domodedovo has been involved in an attack.
In 2004, two female suicide bombers were able illegally to buy tickets from the airport, board jets that exploded in flight and killed 90 people.
According to initial reports, Monday's blast had the force of between five and seven kilograms of TNT.
Around nine foreigners are believed to have been killed in the attack, including at least one Briton, one man from Italy and another from France, as well a Serb national and Zuzana Fialova, an actress from Slovakia.
In March last year 40 people were killed and 100 wounded when two female suicide bombers attacked the Moscow metro system.
The city's second devastating attack in less than a year prompted media commentators to link the blast to the continued violence in the North Caucasus and lament that little had been done to improve security in recent years.
Tensions between ethnic Russians and the 20 million Muslims who make up one seventh of Russia's population, led last month to a string of clashes, which involved thousands of Russian nationalists who attacked passersby of non-Slavic appearance, many of them from the North Caucasus.
Source: Al Jazeera and agencies