An express train traveling from Moscow to St. Petersburg derailed at 9:34 PM on Friday, Nov. 27 , near the town of Bologoye , killing at least 25 people and injuring 87; as of 4 AM Saturday, 32 passengers are reported missing. The #166 train, known as the Neva Express, was carrying over 600 passengers in its 14 carriages; three rear carriages have been damaged due to the accident. A one-meter hole has allegedly been discovered next to the railway track, prompting speculation that this could have been a terrorist act.
On Aug. 13, 2007, the same Neva Express train was derailed due to an explosion; some 60 people were injured then. Coincidentally, in the past few days, there has been an increase in the Russian media coverage  (RUS) of the trial of Maksharip Khidriev, one of the suspects charged in connection with the 2007 attack; an Ingushetia  native, he is alleged to have links to Chechen rebels . (GV posts on the 2007 Neva Express train derailment are here  and here .)
No witness reports of the tragedy seem to have appeared in the Russian blogosphere yet, but there are plenty of reactions still, and below is a small selection.
LJ user peresedov recalls the 2007 accident and the ongoing trial of one of the suspects, and posts this comment  (RUS):
[…] Whether you want it or not, these two events [appear related].
I'd like to ask the experts: to which extent could these two events be interconnected, and is it really possible for Khidriev's associates (he has been proclaimed [Doku Umarov ]'s person) to have prepared an attack like this in two days, and what the hell is going on here in general?
UPD. [LJ user] beri_llii links to a report claiming that the train explosion was carried out by yet another obscure nationalist group: [http://headshotboy.livejournal.com/137255.html]
(The post linked to in LJ user peresedov‘s update has since been deleted, replaced by another one  (RUS) with an explanatory note, which says, among other things, that “the nationalists’ statement” turned out to contain false claims of their involvement in the train blast.)
Some bloggers chose to draw parallels between Friday's train accident, the trial of Maksharip Khidriev, and Kurban Bayram (Eid al-Adha, the Festival of Sacrifice ), a three-day Muslim holiday, whose celebration began on Friday. LJ user warsh wrote this (RUS):
[…] I won't be surprised if this turns out to be a Kurban Bayram “gift” from the North Caucasus rebels (as it was with the attack on the Neva Express in 2007). I'm wishing them to join [the Chechen guerrilla leader Shamil Basayev , killed in 2006] as soon as possible.
And LJ user uliana wrote this  (RUS):
All things considered, the newest Neva Express blast is someone's kurban. A consequence of the fact that those guilty of the first blast have been “appointed”…
LJ user aneta_spb mentions the 2007 attack and the trial, too, but points out  (RUS) to other factors that might have caused the crash:
[…] The suspect in the previous catastrophe [case] has just admitted [his involvement] (and how many more they kept trying to implicate in this case!)
I can imagine what this night is going to be like for Novgorod's doctors… With roads like these… […]
We were just driving from the countryside, gave a ride to a man who, as far as I understood, worked for the Ministry of Emergency Situations or a similar kind of place. He said that this segment of the railway near Bologoye is so rotten in general that they don't have to explode anything there, and this could've been a secondary explosion, too. […]
Exactly – you don't even have to make an explosion. A couple weeks after [the 2007 Neva Express accident], we were on a train and spent some six hours waiting [not far from the site of Friday's crash], because there had been some accident in front of us. And prior to the rushed launch of the [Sapsan high speed train  route], they were doing some urgent repairs, and it's likely that they haven't finished something or done something wrong. […]
And here's a comment  (RUS) on the rescue effort, posted anonymously in the ru_railway LJ community:
In this situation, I'm most upset about the fact that they've spent so much time bragging about the Emergency Situations Ministry's cool new rescue center in Moscow, about all the info that they've got showing on the little screens, and the fact that they are now capable of taking urgent decisions, but what's the use of all these decisions if the local rescue equipment is not in the working condition, and that's why they had to send some [all the way] from Novgorod. The accident took place at 9:34 PM, and the rescuers from Novgorod set out [to the site of the accident] only at 10:40 PM, and it takes two and half hours to ride along those roads, if you can call them roads at all, and that's the best case scenario. They've sent the planes out – but why don't they have anything locally?!