The death toll from one of the worst tornadoes to hit the United States has risen as crews continued to search the rubble for survivors and victims.

Fear has given way to frustration in the shattered American town of Joplin as residents await official word on more than 200 loved ones missing.

Rescue teams have been desperately searching for nearly 1 500 people listed as missing since a tornado ripped through Joplin in the US.