The National Police Agency notified prefectural police forces nationwide Friday of new guidelines regarding the use of firearms, clarifying the circumstances in which officers may be allowed to fire their revolvers.

A rise in serious crimes, as well as a series of incidents this year in which police officers have been killed in the line of duty, have prompted the NPA to issue guidelines that better define the circumstances in which a firearm may be used, agency officials said.

Many observers say the move effectively relaxes the rules regarding the use of weapons by officers in self-defense.