Somalia\'s Shebab insurgents claimed Wednesday 137 hostages they had seized died in a Nairobi shopping mall siege, figures impossible to verify and higher than the number of people officially registered as missing. The Al-Qaeda-linked fighters, in a message posted on Twitter, said \"137 hostages who were being held by the mujahedeen\" had died. They also accused Kenyan troops of firing \"projectiles containing chemical agents\" to end the four-day stand-off.