(LEAD) N. Korea's April 23 SLBM launch ended in failure: officials
(ATTN: ADDS paras 3, 7-10)
SEOUL, May 1 (Yonhap) -- North Korea made a false claim about the April 23 launch of its submarine-launched ballistic missile (SLBM), multiple government sources in Seoul said Sunday, saying the missile is presumed to have e