The U.S. State Department issued a new travel warning for citizens planning on visiting North Korea after rumors of another detained U.S. citizen surfaced.

Citing an unnamed diplomatic source, Kyodo News Service first announced that North Korean officials may have detained an elderly American man last month who had entered the country on a tourist visa. Now, the San Jose Mercury News is identifying the man as Merrill Newman, 85, from Palo Alto in northern California. According to the article, Newman and a neighbor from his retirement community named Bob Hamrdla, had traveled to North Korea through a tour group based in Beijing. The retirement community, Channing House, released a newsletter on Newman and Hamrdla's travels. "Bob Hamrdla no sooner returned from Berlin than he packed up to visit North Korea with Merrill Newman," the newsletter said, according to the report. "Merrill took Korean-language lessons to prepare for their 10-day independent trip. They will be accompanied at all times by two Korean guides." 

Sources revealed that Newman was aboard a plane to leave North Korea when he was removed and detained -- no comments have since been made by Hamrdla. Newman served as an infantry officer during the Korean War. 

Currently, Kenneth Bae is the only confirmed American citizen under North Korean custody, currently serving out a 15-year sentence of hard labor after being found guilty of “hostile acts” against the North Korean regime. Unlike Bae, who is of Korean descent, the rumored other detainee (Newman) is not of Korean descent.

The earlier Kyodo news report said that the man in question entered North Korea for sightseeing and tourism purposes last month on a valid visa, but was arrested for “breaking the law.” Further details have yet to be released or confirmed.

“We are aware of reports that a U.S. citizen was detained in North Korea, but we have no additional information to share at this time,” Nolan Barkhouse, a spokesman for the U.S. embassy in Beijing, told Reuters. Barkhouse added that the U.S. still advises against travel to North Korea, citing that “U.S. citizens crossing into North Korea, even accidentally, have been subject to arbitrary arrest and long-term detention.”

Since the traveler was reportedly on a tourist visa, it is assumed he was part of a pre-arranged tour group from nearby Beijing, where most tours to North Korea originate.

“I can guarantee it was not one of our customers,” Chris White, from the Beijing-based Young Pioneer Tours, told Washington-based NK News. The number of tour groups operating in North Korea is rather small, so information of a detained tourist would disseminate pretty quickly.

Simon Cockerell, who works for the British-owned Koryo Tours, couldn’t disclose any new information either, telling NK News, “in 20 years of operation we have never once had any of our tourists arrested or detained, and we continue to operate all tours as usual.” With respect to the tourism agency rumor mill, Cockerell added, “We are keeping an eye on the news but have no specific extra information at this time.”

Though threats from North Korea to the U.S. persist, travel to the remote nation has increased. Up to one-third of all recent Western tourists to North Korea hail from the U.S.

Still, the U.S. State Department advises against travel after several Americans have been arrested in the past.  “Since January 2009, four U.S. citizens have been arrested for entering North Korea illegally, and two U.S. citizens who entered on valid DPRK [North Korea] visas were arrested inside North Korea on other charges,” the newest travel warning reads.