A girl shoots an arrow at a picture of President Obama during an event to mark International Children's Day in Pyongyang, North Korea, on June 1. (Kim Kwang Hyon/AP)

North Korea said Friday that it has detained an American tourist for unspecified violations, marking the latest in a string of legal problems and arrests for those visiting the authoritarian nation.

In a two-sentence statement, the North’s state-run news agency said that a U.S. citizen it identified as Jeffrey Edward Fowle had entered the country on April 29 and acted “contrary to the purpose of tourism.”

“A relevant organ of the DPRK detained him and is investigating him,” the North said, using the initials of the country’s formal name, the Democratic People’s Republic of Korea.

North Korea did not elaborate on Fowle’s alleged violations, but his detention raises further concerns about those traveling to the North, even as a part of sanctioned tour groups. In a travel warning updated last month, the U.S. State Department strongly advised against visiting the North and warned about arbitrary arrests, long-term detention and punishment or expulsion for “activities that would not be considered criminal outside North Korea.”

“Do not assume that joining a group tour or use of a tour guide will prevent your arrest or detention by North Korean authorities,” the State Department said.

At least three U.S. citizens are detained in the North, including Kenneth Bae, a Christian missionary who was sentenced last year to 15 years of hard labor on charges of trying to overthrow the government. Another American, Matthew Todd Miller, was taken into custody two months ago after tearing up his visa and declaring that he was “not a tourist,” New Jersey-based Uri Tours said in a statement on its Web site.

State Department spokeswoman Marie Harf confirmed that the United States knows of the latest case but said she could not provide details. The detainee has not signed a waiver of federal privacy rights that forbid government disclosure of most information about private citizens.

“We are aware that a U.S. citizen has been detained in North Korea. This is the third U.S. citizen that has been detained in North Korea. Obviously, there is no greater priority for us than the welfare and safety of U.S. citizens abroad. And we don’t have any additional information to share at this time.”

Since 2009, North Korea has detained at least nine U.S. citizens, at times using them as bargaining chips to extract high-profile rescue visits from former presidents Bill Clinton and Jimmy Carter.

The latest detentions, though, pose a greater challenge for Washington, which has gone more than two years since its last dialogue with Pyongyang. The United States does not maintain diplomatic ties with the North and counts on the Swedish Embassy in Pyongyang to help Americans when needed.

Japan’s Kyodo News agency, citing diplomatic sources, said that Fowle was detained in mid-May — just before he was about to leave the country — “apparently for having left behind a Bible at the hotel where he had been staying.”

North Korea’s constitution grants religious freedom, but in practice, the North considers religion incompatible with — and threatening to — the state-sponsored personality cult of the ruling Kim family. Last week, the North said it sentenced a South Korean Baptist missionary to a life term of hard labor for a series of “grave infringements,” including an attempt to set up underground churches.

According to a United Nations report on North Korean rights violations, Pyongyang is particularly hostile toward Christianity, which it has “compared to a drug, narcotics, a sin, and a tool of Western and capitalist invasion.”

The North does have a handful of sanctioned churches, but they are carefully controlled showpieces stocked with Workers’ Party loyalists. The United Nations said the churches are used to help the government gather foreign currency, as members are asked to contact foreigners and conduct fundraising.

Anne Gearan contributed to this report.