Story highlights North Korean state-run news agency accuses professor of "hostile acts"

Tony Kim, also known as Kim Sang Duk, is third American detained in North since 2015

(CNN) North Korea has accused an American detained since April of attempting to overthrow the government.

The state-run Korean Central News Agency said Wednesday that Tony Kim -- also known as Kim Sang Duk -- was detained for "hostile acts" toward the Pyongyang regime.

Kim was seized on the morning of April 22 at Pyongyang International Airport as he attempted to leave the country following a stint as a professor of accounting at the Pyongyang University of Science and Technology, KCNA said.

Americans detained in North Korea Currently held: • Otto Warmbier, a University of Virginia student, was sentenced to 15 years of hard labor in 2016 for removing a political sign.

• Kim Sang Duk, also known as Tony Kim, a university professor, was detained in Pyongyang in 2017 and accused of attempting to overthrow the government.

• Kim Dong Chul, the president of a company involved in international trade and hotel services, was arrested in 2015 and is serving 10 years on espionage charges. Americans released in 2014: • Kenneth Bae served nearly two years of hard labor after accusations he was part of a Christian plot to overthrow the regime.

• Matthew Todd Miller was also accused of "hostile acts" after tearing up his tourist visa and seeking asylum after entering North Korea.

• Jeffrey Fowle spent five months in a North Korean prison after being caught with a Bible inside the country.

The report added Kim "was intercepted for committing criminal acts of hostility aimed to overturn the (Democratic People's Republic of Korea) not only in the past but also during his last stay before interception."

He is being held while an investigation is underway, KCNA said.