A bus bombing in the southern Russian city of Volgograd has killed at least five people and wounded 27 more, including a child, authorities said, according to Russian news agency Interfax. The blast was the deadlinest such attack outside Russia's volatile North Caucasus region in almost three years, NBC News reported. The Russian Investigative Committee said the suspect was Naida Asiyalova, a 30-year-old woman from Dagestan whose husband is believed to have had links to militant insurgents, according to Russian state television channel Russia 24; a similar report by Interfax said investigators believe the suspect was the wife of an Islamist militant. Although there was no immediate claim of responsibility, insurgents who say they are fighting to create in Islamic state in Russia's mostly Muslim North Caucasus have carried out deadly bombings there and outside of the region. The last such bombing was a suicide bombing that killed 37 people at a Moscow airport in January 2011.