1 of 4. North Korean soldiers attend military drills in this picture released by the North's official KCNA news agency in Pyongyang March 20, 2013. KCNA said this picture was taken on March 20, 2013. 
 
 SEOUL (Reuters) - North Korea issued an air raid warning on Thursday, South Korea's Unification Ministry said quoting a radio broadcast monitored in Seoul. A news report said the warning appeared to be part of a defense drill. 
 
 The warning was issued at 0032 GMT and carried a message to military units to stand ready, but the action appeared to be a drill under an air raid scenario, Yonhap news agency said. 
 
 An official at the Unification Ministry, which handles ties with the North and monitors North Korea's news broadcasts, confirmed air raid warning on Thursday morning. 
 
 The official could not confirm whether the warning was part of a drill. The two Koreas remain technically at war under a truce that ended their 1950-53 conflict. Tensions have been high with the rivals exchanging verbal barbs. 
 
 North Korea has been conducting large-scale military drills coinciding with annual exercises by the South Korean and U.S. forces running to the end of April. The allies have stressed the drills are strictly defensive in nature. 
 
 (Reporting by Jack Kim; Editing by David Chance) ||||| Story highlights North Korea is verbally "firing back" at recent moves by the U.S., an analyst says 
 
 Pyongyang has expressed anger that the U.S. is flying B-52s over South Korea 
 
 The flights are part of annual military exercises 
 
 Tensions on the Korean Peninsula have flared since the North's latest nuclear test 
 
 The North Korean military issued a fresh burst of ominous rhetoric Thursday, warning that U.S. bases in Guam and Japan are within its "striking range." 
 
 The statement from the Supreme Command of the Korean People's Army, carried by the North's state-run news agency, follows the announcement by the United States this week that its B-52 bombers were making flights over South Korea as part of annual military exercises. 
 
 "The U.S. should not forget that the Andersen Air Force Base on Guam where the B-52s take off and naval bases in Japan proper and Okinawa where nuclear-powered submarines are launched are within the striking range of the DPRK's precision strike means," the North Korean military said Thursday. 
 
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 Despite Pyongyang's rhetoric, no U.S. Navy submarines are based in Okinawa or anywhere else in Japan, although they may make calls at U.S. bases there. DPRK is short for Democratic People's Republic of Korea, North Korea's official name. 
 
 Citing what it called the United States' "nuclear blackmail and threat," the North said it that it, too, would "take corresponding military actions." 
 
 Pyongyang had already reacted angrily to the B-52 flights, warning Wednesday of "strong military counteraction" if the planes made more sorties over the Korean Peninsula. 
 
 Angry words after new sanctions 
 
 Tensions have spiked in the region since North Korea carried out its latest underground nuclear test last month, the first under its new young leader Kim Jong Un, prompting the United Nations Security Council to respond by toughening sanctions on the secretive regime. 
 
 The sanctions enraged the North further, and during the week when the Security Council was voting on them, it ratcheted up its threats, suggesting it could carry out a pre-emptive nuclear strike on the United States and South Korea. 
 
 Although analysts and American officials say Pyongyang is still a long way from being able to carry out such an attack on the U.S. mainland, the United States' bases in Japan and Guam appear to be within range of the North's conventional weapons. 
 
 In its comments Thursday, "the Kim Jong Un regime is just firing back" at its enemies in response to the B-52 flights and the military exercises of which they're a part, said Lee Jung-hoon, a professor of international relations at Yonsei University in Seoul. 
 
 He said that the U.N. sanctions were also likely to be fueling the North's ire, but that the regime's threats were largely driven by domestic concerns. 
 
 "They're doing all this to prop up the regime," Lee said. 
 
 The military first strategy 
 
 Since Kim took over from his father as the head of the North Korean government in late 2011, he appears to have maintained the pursuit of a stronger military deterrent rather than adopting a more conciliatory approach to relations with South Korea and the United States. 
 
 The result has been a major foreign policy headache for U.S. President Barack Obama, with Kim showing more interest in dialogue with the basketball star Dennis Rodman than U.S. diplomats. 
 
 As well as the nuclear test, his government has conducted two long-range rocket launches -- one that failed and one that succeeded -- both of which were widely viewed as tests of ballistic missile technology. 
 
 Kim has also revamped the military's leadership, ousting some generals and promoting others. 
 
 The nuclear test and rocket launches have shattered hopes of any new talks on the North's nuclear program in the near future. 
 
 Indeed, Pyongyang has said recently that the program is not up for negotiation and announced that previous nonaggression treaties with Seoul no longer apply. 
 
 A new North Korea 
 
 The regime's unabashed declarations about its nuclear weapons, which it had been much cagier about in the past, show that "it's not the same North Korea as 10 years ago," Lee said. 
 
 The United States and other global powers need to "formulate a whole new strategy" to address the changed situation, according to Lee. 
 
 "The way we've been dealing with it for the past two decades has failed," he said of the regime. "It has become close to being able to deploy nuclear weapons." 
 
 Although U.S. officials say they don't believe North Korea is in a position to strike the United States at the moment, Defense Secretary Chuck Hagel last week announced plans to deploy additional ground-based missile interceptors on the West Coast as part of efforts to enhance the nation's ability to defend itself from attack. 
 
 "The reason that we are doing what we are doing, and the reason we are advancing our program here for homeland security, is to not take any chances, is to stay ahead of the threat and to assure any contingency," Hagel said at the time.
– After the US announced it's flying B-52 bombers over South Korea, the North is issuing its latest warning: US military bases in Guam and Japan are in its "striking range." Said the country's military: "The US should not forget that the Andersen Air Force Base on Guam where the B-52s take off and naval bases in Japan ... where nuclear-powered submarines are launched are within the striking range of (North Korea's) precision strike means." Pyongyang said it would "take corresponding military actions" over US "nuclear blackmail and threat." The bases do seem to be within the North's conventional-weapons range, CNN notes. Meanwhile, the North announced an air raid warning today, calling on military units to be ready, according to South Korea—but the warning was apparently linked to a defense drill, Reuters reports.