Speaking to South Korea lawmakers during their visit to military headquarters, Adm. Jung Ok-keun said the KN-02 missiles "are estimated to have a range between 130 kilometers (80.7 miles) and 160 kilometers (99.4 miles)," Yonhap news agency reported.
The report said South Korean defense officials had believed the missiles' range was only up to 120 kilometers or 74.5 miles. Even in that range, however, the missiles were seen as a threat to a major western South Korean naval port and a key U.S. military hub south of Seoul.
Monday's tests off North Korea's east coast included five surface-to-surface KN-02 rockets. South Korean defense officials said they were believed to be the first such tests in three months.
Jung told the lawmakers he was waiting for a briefing from his officials on where the missiles fell into the East Sea, Yonhap said.