Korean residents in Japan on Thursday expressed anger and disappointment at North Korea’s announcement that it has succeeded in detonating its first hydrogen bomb, saying it could fuel anti-Korean sentiment and spoil ongoing grass-roots efforts to promote peace in the Korean Peninsula.

“This is the fourth time North Korea has carried out a nuclear test, but every time it has only inflicted damage on the Korean community in Japan,” said Kwak Jinwoong, 49, director of Osaka-based Korea NGO Center.

“Every time, it has sparked criticism against — and alarm of — North Korea in Japan, resulting in Koreans in Japan being made targets of such sentiment.”

Kwak said North Korea’s test “absolutely cannot be tolerated,” noting that it raises tensions in the peninsula and goes against international peace-building efforts, including the six-party talks involving Japan, the U.S., China, South Korea, North Korea and Russia, to defuse tension.

Kwak worried that “Zainichi” Korean residents of Japan, who already faced frequent acts of racism and discrimination, might see attacks against them intensify in the future.

“I don’t think there is a single Korean resident in Japan who endorses the test,” he said.

In Tokyo, some 50 people protested in front of the headquarters of the General Association of Korean Residents (Chongryon), considered North Korea’s de facto embassy in Japan, while police beefed up security around the complex.

The protesters, including members of the pro-Seoul Korean Residents Union in Japan (Mindan), displayed banners demanding Pyongyang relinquish nuclear weapons.

A Chongryon spokesman said the group did not intend to release a statement on the nuclear test and he had “nothing to say.”

Meanwhile, Do Sangtae, a 74-year-old Korean resident in Toyohashi, Aichi Prefecture, said the North Korean announcement was “disappointing.”

Do heads a nonprofit group “Sanzenri Tetsudo” (“Three Thousand Miles Railway”), which he set up in response to the North-South Joint Declaration on June 15, 2000.

The group has campaigned to build a railroad in the Korean Demilitarized Zone, with an eye to eventually connecting it to railways on both sides of the peninsula.

A second-generation Korean resident and business owner, Do worried that the nuclear test might adversely affect a planned visit in mid-February by himself and 14 other Zainichi Koreans to the Kaesong industrial zone, a Seoul-funded industrial park in North Korea.

It would be the first time Korean residents in Japan are allowed to visit the area, Do said, adding that they were looking into investing in businesses operating in the industrial park, which currently employed some 54,000 people.

Do expressed hope, however, that his group could continue grass-roots activities to help improve inter-Korean relations.

“The North and South Koreans are the same ethnic people,” he said.

“It is the tens of millions of ordinary citizens living there who are most affected (when political tensions rise). It’s easy to fuel confrontation in times like this, but we should continue to search for a way to open a dialogue. The Zainichi people might be best suited to fulfill that role.”