A South Korea citizen was repatriated by North Korea on Tuesday through the village of Panmunjom on the inter-Korean border inside the Demilitarized Zone, or DMZ.

According to South Korean reports, the man was a 34-year-old surnamed Suh, who had illegally entered North Korea on July 22. Having returned to South Korea, he is now under investigation by South Korean authorities, according to Yonhap news agency.

It is not known, as this stage, how Suh entered North Korea, though Yonhap stated quoted an unnamed source stating that he had entered the country via China.

Suh’s motives are also unknown.

In recent years, there have been a handful of defections northward across the DMZ, sometimes by disgruntled people with histories of business failures or family problems. Also, it is not uncommon for fishermen to be washed south or north of the maritime frontier, ending up on the wrong side of the border.

Moreover, South Korean Christian missionaries, who enter North Korea from China, are occasionally arrested inside the North. Three South Korean missionaries, and three other southern citizens, are now detained by North Korea, according to Seoul.

However, non-governmental groups allege that the number of South Koreans held by North Korea is far higher and includes POWs from the 1950-53 Korean War, fishermen who were abducted – even journalists and flight crew from a South Korean civil aircraft hijacked to North Korea in 1969.

And with the two Koreas technically in a state of war, troops on both sides have orders to shoot to kill anyone trying to cross the border.

In 2013, South Korean troops in a guard post on the Imjin/Han River estuary shot dead a South Korean attempting to swim to North Korea. And last year, a North Korea soldier at Panmunjom was shot multiple times, but survived, when North Korean troops opened fire after he dashed over the border.

Meanwhile, frustrations are apparent in both North Korea and in the United States over the much-anticipated but now moribund denuclearization process.

But on the peninsula, Tuesday’s move by North Korea dovetails with a broader trend of détente that is gradually settling over inter-Korean relations.

South Korea’s presidential office on Tuesday released a lengthy English-language report on “Major Post-Panmunjom Declaration Achievements.” The Panmunjom Declaration was the document signed by North Korean leader Kim Jong-un and South Korean President Moon Jae-in after their April summit.

The report included, among the achievements: the re-establishment of cross-border military hotlines; regular military talks; the halt of cross-border propaganda broadcasts; reciprocal visits by envoys, sports persons and sports teams; the establishment of a joint Korean team for this year’s Asia Games from August 18 to September 21 in Jakarta; a reunion of divided families to be held from August 20 to 26; and consultations on reconnecting inter-Korean roads and rail lines.

Even so, issues remain.

North Korean media regularly claims that a dozen restaurant workers, who reportedly defected to the South from China in 2014, were, in fact, tricked by the South Korean intelligence service. That allegation has been backed up by South Korean media reports, featuring interviews with related parties.