North Korea has threatened to target US airbases in Okinawa and Guam as it issued an air raid alert on Thursday and ordered its military to stand ready, the country’s state media reported.

"The United States is advised not to forget that our precision target tools have within their range the Anderson Air Force base on Guam where the B-52 takes off, as well as the Japanese mainland where nuclear powered submarines are deployed and the navy bases on Okinawa," the North Korean command spokesman was quoted as saying by KCNA news agency.

The threats came as a response to the use of nuclear-armed US B-52 bombers in joint war games South Korea held with the US. "We cannot tolerate the US carrying out nuclear strike drills, setting us as targets, and advertising them as strong warning messages," the spokesman said.

The air raid alert was issued at 9:32 am local time (00:32 am GMT) with military units and civilians told to take cover, Korean Central Television said.

A news report by South Korea’s Yonhap news agency suggested that the warning appears to be a part of a military drill, though this has not been confirmed by Pyongyang.

This comes amid growing tensions on the Korean Peninsula and ongoing saber-rattling that followed the UN Security Council's imposition of strict sanctions on Pyongyang over its third underground nuclear test in February.

On Monday, the US said that every military resource at its disposal, including its nuclear arsenal, would be available to South Korea in the event of a confrontation with the North.  

Earlier in March, Pyongyang threatened all-out nuclear war with the US and South Korea after the two countries began joint military drills on the Korean Peninsula. The North also nullified the 1953 armistice that ended the Korean War, claiming the drills were preparations for an invasion.

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