Chechen connections? Apparently so as a firefight last night left one suspect dead and another still at large.

Two suspects in the Boston Marathon bombing killed an MIT police officer, injured a transit officer in a firefight and threw explosive devices at police during their getaway attempt in a long night of violence that left one of them dead and another still at large Friday, authorities said as the manhunt intensified for a young man described as a dangerous terrorist.

The suspects were identified to The Associated Press as coming from the Russian region near Chechnya, which has been plagued by an Islamic insurgency stemming from separatist wars. A law enforcement intelligence bulletin obtained by the AP identified the surviving bomb suspect as Dzhokhar A. Tsarnaev, a 19-year-old who had been living in Cambridge, just outside Boston, and said he “may be armed and dangerous.”

Two law enforcement officials told the AP that Tsarnaev and the other suspect, who was not immediately identified, had been living legally in the U.S. for at least one year.

Information is still coming in, updates throughout the day.