SEOUL (Reuters) - North Korea said on Monday it would put two U.S. tourists on trial for committing crimes against the state, dimming any hopes among their families that they would soon be released.

"Their hostile acts were confirmed by evidence and their own testimonies," said the official KCNA news agency, referring to Jeffrey Fowle and Matthew Miller who are being held by the isolated country. It gave no details on when they would face court.

Fowle, a 56-year-old street repairs worker from Miamisburg, Ohio, was arrested after entering North Korea as a tourist in late April.

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Miller, 24, was taken into custody by North Korean officials after entering the country in the same month, ripping up his tourist visa and demanding asylum, according to state media.

Another U.S. national, Kenneth Bae, a Christian missionary who had been arrested in November 2012, was convicted and sentenced to 15 years hard labor last year.

Pyongyang has detained a number of U.S. citizens in the past, using them to extract visits by high-profile figures, including former U.S. President Bill Clinton.

But it has twice canceled visits by Robert King, the U.S. special envoy for North Korean human rights issues, to discuss Bae's case.

The KCNA announcement comes a day after Pyongyang fired two short-range ballistic missiles, defying a U.N. ban on the reclusive state testing such weapons.

North Korea periodically accuses the United States of military hostility and conspiracy to overthrow its leadership. The two states have been locked in a tense diplomatic conflict over Pyongyang's nuclear and missile programs.

In May, the U.S. State Department issued an advisory urging Americans not to travel to North Korea because of the "risk of arbitrary arrest and detention" even while holding valid visas.

North Korea has detained and then released other Americans in the past year, including Korean War veteran Merrill Newman, whom it expelled after holding him for more than a month after accusing him of being a war criminal.