MINERALNYE VODY, Southern Russia — Authorities in a southern Russian province rocked by a series of deadly bomb explosions declared a day of mourning on Monday amid a huge security operation to capture those responsible. Officials have linked the bombings that killed 23 people and injured more than 100 to Chechen rebels. Newspapers said Saturday's blasts were a setback for Moscow's attempts to push the slow-burning Chechnya conflict out of the public eye. A municipal government spokeswoman in the spa resort town of Mineralnye Vody said six victims had been buried on Monday. They were among 21 killed when a booby-trapped car exploded at the entrance to a busy morning market. The funerals were supposed to be low-key affairs held at different cemeteries but hundreds of mourners turned up with flowers to express their grief. Police guarded the processions as authorities endeavored to stave off feared new attacks. Long funeral corteges rolled through the small town whose streets were lined with tearful residents.