Volgograd is more than 400 kilometers ( 250 miles ) north-northwest of Dagestan 's northern boundary . Investigators say they think a woman from Dagestan set off the blast . The explosion occurred at about 12:30 p.m. in front of an apartment building on West 23rd Street near Sixth Avenue and was followed by several other blasts that injured more than 100 people -- some seriously, officials said. A criminal investigation is under way , authorities say .
Investigators say they think a woman from Dagestan set off the blast . The explosion occurred at about 12:30 p.m. in front of an apartment building on West 23rd Street near Sixth Avenue and was followed by several other blasts that injured more than 100 people -- some seriously, officials said. A criminal investigation is under way , authorities say .