Another suicide bombing killed two policemen in the troubled southern republic of Ingushetia on Monday, rattling nerves around Russia, which has seen five terrorist attacks that have left nearly 60 people dead and scores injured since two deadly explosions hit Moscow's metro system a week ago.
The latest blast came after a man entered a police station in the town of Karabulak, where about 50 officers were gathered for their morning briefing.
"The man approached two police guards," the official ITAR-Tass agency quoted an Ingush security official as saying. "He seemed suspicious to them and when they attempted to check his documents, he triggered the explosive device."
Two officers were killed, and a third injured. A second explosion detonated in a nearby parked car a few minutes later – a tactic frequently employed by north Caucasus militants, aimed at striking investigators as they gather at the attack scene – but no one was harmed.
A flurry of attacks
Another republic that has seen growing terrorist violence is Dagestan, a multiethnic Caspian province, where suicide bombers struck twice last week. On Sunday, two massive bombs planted beneath the railway tracks near the Dagestani capital of Makhachkala destroyed a freight train, which had come from Moscow, but did not cause any casualties. (Video report below.)
In what is becoming a familiar tactic, the first bomb derailed the train and the second detonated a few minutes later, Russian media reports said.
"The second device was placed near the railway track, 25 meters from the first one, and was meant to be blown up when police and investigators arrived at the scene," ITAR-Tass reported.
Moscow metro bombers identified
Russian investigators have now identified the two bombers responsible for the Moscow metro attacks a week ago, which killed 40 people, and both appear to be young women from Dagestan, or the kind of attacker that Russian security forces have dubbed "black widows."
Ms. Sharipova, a graduate in psychology who worked as a teacher in a village near Makhachkala, had no known links with Islamist militants and appears not to fit the standard "black widow" definition of a woman taking revenge for the loss of her menfolk at the hands of Russian security forces.
"The three of us – my wife, my daughter and I – had gone to Makhachkala to shop" on March 28, Mr. Magomedov told Novaya Gazeta. "My daughter said she was going to meet a friend. Later she called on her mobile to say that she would return home on her own. That's the last time we heard from her,” he said.