The National Weather Service issued tornado warnings for a large swath of central US, including the states of Kansas, Missouri, Iowa and Nebraska. The warning came today as security concerns escalate in the aftermath of 40 devastating tornados that have ripped through Oklahoma, Kansas and Iowa since mid May, Voice of Russia reported . Oklahoma was hit hardest, with twisters killing 24 residents and leveling dozens of homes. US President Barack Obama has ordered to allocate deferral funds to the state in West South Central US.