MOSCOW — An explosion killed at least 9 people and injured about 50 adults and children in the metro of Saint Petersburg, Russia, on Monday, according to Russian news agencies.

The crowded metro train hit by the attack was traveling between Sennaya and Tekhnologichesky Institut stations at about 3:00 p.m. Witnesses in one of the cars described a “deafening blast, sharp smell, and smoke.” Surviving victims were bleeding, many with hair burned off their heads and bodies. On seeing the smoke, “passengers in other wagons panicked, two women fainted,” according to a local student named Polina speaking to the Paperpaper internet outlet.

Senator Victor Ozerov, responsible for security at the Russian Federal Assembly said that “there are all the signs of a terrorist attack.” Izvestia reported that according to a special unit veteran investigating the attack, the bombing was carried out by a jihadist suicide-bomber.

The first images of the tragedy featured terrified, bloodied passengers, bloodied floors, blasted windows and doors in the bombed metro carriage.

In reaction, Russian authorities closed down the metro, which caused transport issues and traffic jams in Saint Petersburg. Taxi drivers gave people free lifts.

The attack coincided with a Kremlin-organized annual “Truth and Justice” event in St. Petersburg attended by President Vladimir Putin and 500 journalists from all over Russia.

Soon after the attack LifeNews posted a video of President Putin smiling and hugging Belarusian President Alexander Lukashenko. Both leaders expressed condolences to the victims’ families.

Since Vladimir Putin came to power in 1999, Russians have heard about hundreds of terrorist attacks—bombed apartments, cars, buildings, trains, and airplanes.

Putin has taken advantage of these so frequently to consolidate his power that people often tend, with no proof, to believe conspiracy theories suggesting the involvement of Russia’s special services or various powerful clans behind the attacks.

Commenting on the tragedy, a Pro-Kremlin writer and political analyst, Alexander Prokhanov, said on the “Vremia” television show that both the anti-corruption protests this month and the attack on the metro were planned by the same opposition center, as if calling for authorities to conduct even a bigger crackdown on the opponents.

On Monday Russian Internet bloggers commented on the violent attack on peaceful commuters in the heart of Saint Petersburg.

Some blamed the tragedy on Russia’s involvement in Syria, others on the poor work of the FSB, the state security service. “Authorities have found out how to distract people’s attention from protests,” a blogger, Daria Zhukova, said in her post on Republic.ru website.

On the same website another blogger, Vasya Batareykin, referred to the recent air crash in Sochi that killed 92 passengers, musicians, and volunteers on their way to Syria: “It will be the same as with that plane—nobody will remember the reasons; authorities will turn the attack into hypocrisy, capitalizing the tragedy into the points for their popularity rating.”

Seven years ago Moscow was shaken by a series of terrorist attacks on the metro. Two women carried out suicide bombings at Moscow metro stations during the rush hour of March 29, 2010. At least 40 people were killed, and more than 100 injured.

On Monday, people in Moscow could feel the pain of victims and families in Saint Petersburg. But at the fashionable Jean-Jacques Café, one young man asked a friend, “I wonder who are they going to blame for this now.”

To which his friend responded, "I always wonder, whoever kills people, why they do not blow up government buildings instead of targeting completely innocent metro passengers.”