North Korea has arrested a United States university student for engaging in "hostile activities", the Korean Central News Agency reported on Friday. According to AP, the report said that authorities are questioning the student, who they claim entered the country as a tourist and allegedly plotted to undermine the North's system.

The arrest comes three months after North Korea had released a 21-year-old South Korean student, who was a US green card holder, six months after he was detained for allegedly crossing the border between the two countries illegally. According to AFP, Joo Won-moon’s release came after he was presented to the media in Pyongyang and read out what appeared to be an officially approved statement, admitting his guilt and singing North Korea's praises.

Tensions between North Korea and the US have flared after Pyongang confirmed it had tested a hydrogen bomb earlier this month. The US responded by flying a massive B-52 warplane over South Korea, claiming the show of strength in response to the nuclear test.