An explosion near a hospital in the southern Russian city of Nazran killed at least one person and injured three others.
The blast occurred around 4 p.m. (1200 GMT) near Nazran, one of the main cities in Ingushetia, a Caucasus region bordering Chechnya, said Oleg Ugnivenko, a duty officer for the federal Emergency Situation Ministry. The blast occurred about 50 meters (160 feet) away from the main regional hospital, he said.
All the casualties appeared to be passers-by, Ugnivenko told The Associated Press.
Nazir Yevlaiyev, a spokesman for the regional Interior Ministry, said the blast was caused by an explosive device planted near a natural gas pipeline.
Ingushetia regularly suffers spillover violence from war-shattered Chechnya to the east, but it also has homegrown militants and criminal groups fighting local authorities.