CHICAGO:- The US state of Oklahoma plans to become the first in the country to use nitrogen gas to execute condemned prisoners, law enforcement officials have announced. The state intends to adopt the new execution method as prison officials are unable to acquire the necessary drugs for lethal injections - the method currently employed by all American states that carry out the death penalty. States have struggled to obtain lethal injection drugs as manufacturers and suppliers increasingly have shunned them under pressure from death penalty opponents.–AFP