TOKYO — The Japanese government issued a state of emergency at a nuclear power plant Friday after a cooling system failure in the wake of the giant earthquake and tsunami off the east coast of the Pacific nation.

An administrator at the Tohoku Electric Power Co's Onagawa facility said the process for the cooling reactor is "not going as planned," adding that "nuclear emergency situation" has been declared. The company asked people nearby to stay calm, the official TV news channel NHK reported.