Two surface-to-air missiles fired by Pyongyang near its border with China may have landed in North Korean territory, a Japanese news agency reported, citing security sources. Kyodo News agency cited a "security source" in China as saying the missiles were fired by mistake in the direction of China during a military drill, and the missiles appeared to have landed in North Korean territory. But the agency also cited a "Western military source" as saying the short-range missiles were test-fired in an eastern direction from the North's eastern coast, toward the Sea of Japan. The agency said it couldn't immediately reconcile the conflicting reports, and the exact time of their launch was unknown. Pyongyang shocked Tokyo and other nations when it test-fired a ballistic missile over northern Japan in 1998. It has since test-fired short-range missiles many times, including one that was launched into the Sea of Japan in May last year. In 2003, it test-fired short-range land-to-ship missiles at least three times during heightened tensions over its nuclear weapons program. Japan's Defense Ministry said it could not confirm the report. But Tokyo "constantly monitored the military activities of neighboring countries," a spokesman said on condition of anonymity, citing regulations. Kyodo quoted an unnamed defense official as saying the government would not inform the public of the possible misfires because they did not threaten Japan's security. Yang Chang-seok, spokesman for South Korea's Unification Ministry, which deals with North Korean affairs, said the ministry could not confirm the report. Calls to US military and embassy officials in Tokyo and China's Defense Ministry in Beijing went unanswered Wednesday night. White House press secretary Scott McClellan said Wednesday that Bush administration officials were still looking into the reports. Analysts say North Korea is developing long-range missiles capable of reaching Alaska, Hawaii or perhaps other states on the West Cost of the United States. Japan and the United States are developing a joint ballistic missile defense system, and Tokyo has said it will launch two spy satellites by March 2007 to monitor North Korea and other trouble spots. There is no evidence North Korea has managed to load a nuclear warhead on a missile, but the isolated communist state claims to have produced nuclear weapons. Last September, Pyongyang agreed at multilateral talks to abandon its atomic weapons program in exchange for aid and security guarantees. However, no progress has been made since then on implementing the accord.