At around 2:45 p.m. local time on Monday, a bomb went off on a train traveling between two metro stations in St. Petersburg, Russia, occurring shortly before the evening rush hour was set to begin. Russian state news reported that ten people were killed and at least 50 more were wounded by the blast. Immediately following the attack, parts of the Russian metro were shut down and travelers were evacuated from the tunnels.
As of 10:30 a.m. Eastern time on Monday, no known terrorist groups have claimed responsibility for the bombing, and Russian authorities say an investigation is underway.
Russian President Vladimir Putin is due to hold a press conference soon about the attack.
Here are five things to know about the attacks:
1. The Bomb Went Off Between Stations
The explosion took place on a train traveling between two station hubs: the Sennaya Square and Technology Institute stations, areas typically crowded with commuters going to and from their jobs. Because the blast occurred in the mid-afternoon, the stations were not as packed as it normally would have been in the morning or the evening.
The stations were evacuated following the blasts, and pictures and videos began to emerge on Twitter showing the chaotic aftermath and a severely damaged metro train at the scene.
2. Only One Bomb Went Off
As of now, authorities have said that there was only one blast that occurred. It came from an explosive device placed on the train car by an unknown perpetrator. There is so far no indication that any other areas of the city or in Russia generally are in immediate danger, as the attack appears to be isolated to the subway stations already affected.
3. There Was a Second, Undetonated Bomb
Authorities found a second, undetonated device at the scene. It has been safely removed. The presence of the second device suggests that the attack was supposed to be larger than it was, and it is unclear exactly why that second device did not go off. So far, no further bombs have been found, although the affected metro stations, and much of the service area around them, remain closed.
4. Russian President Vladimir Putin Was in the City
Putin was in St. Petersburg at the time of the blast. He was there to meet with the President of Belarus, Alexander G. Lukashenko, and to speak at an event of the All-Russia People’s Front. The Front is a nationalist political group founded by Putin. It is unclear — but unlikely, given the nature of the attack — that the bomb blast was connected to Putin’s visit, or that Putin himself was a target.
5. Putin Isn’t Ruling Out Terrorism
In earlier comments on the attacks, Putin said it was too early to speculate as to the cause, be made it clear that terrorism was a clear possibility and that authorities were investigating to that effect. Putin said that Russian intelligence and police forces “will do everything to find out the causes of what had happened.” He also expressed condolences to the families of the victims. U.S. President Donald Trump has yet to issue a statement on the attack.