The number rose of hostages thought to have died in the four-day al Qaeda siege at the Algerian gas plant rose Monday to at least 48 after the 25 mostly burnt bodies found at the complex were all identified as those of captives. Still as many as 20 hostages remain unaccounted for, say the Algerian authorities, who promise a definitive death toll as soon as their searches of the vast complex is finished. Five suspected Islamist attackers were reportedly arrested on Sunday.