BEIJING -- Chinese guards dragged a North Korean asylum-seeker away from a South Korean visa office Thursday after punching and kicking diplomats who tried to stop them -- prompting a strong protest from the South Korean government.
The incident, barely a month after Beijing settled a similar row with Japan, comes amid tougher measures by China to stem a wave of North Korean asylum-seekers entering foreign missions in China.
Dozens of North Koreans fleeing famine and repression have sought refuge at U.S., Japanese and other foreign diplomatic offices in China.
A total of 18 are now in the South Korean office, including the 15-year-old son of the North Korean man hauled away Thursday. The teen-ager remained inside the diplomatic office after his father was taken away. Two North Koreans have been in the Canadian Embassy since Saturday.
In the latest sign of China's hardening attitude, a Foreign Ministry spokesman said foreign diplomatic missions have been informed they must hand over to Chinese police people who have sought refuge in their offices.
Such unauthorized entries "not only harm the security of those embassies and interfere with their normal function, but also pose a challenge to the Chinese law and interfere in security and stability in China," spokesman Liu Jianchao told reporters.
Liu repeated China's assurance that cases would be handled "in accordance with international law, the domestic laws of China and humanitarian principles."
Canadian and other foreign missions confirmed they received the note Wednesday evening.
Reynald Doiron of Canada's Department of Foreign Affairs and International Trade said Chinese authorities "have not attempted to enter the embassy. We expect them to adhere to their obligation to respect our diplomatic premises."
Liu denied the letter to missions indicated any change in Chinese policy. However, it appeared to signal an end to a more accommodating attitude under which Beijing allowed 38 North Korean asylum-seekers to leave over the past two months.
The latest asylum bid began when the North Korean father and son entered the visa office a few blocks from Seoul's embassy Thursday morning, the South Korean official said.
Chinese guards entered and took the man outside, where he was held temporarily, said the official, who spoke on condition of anonymity. South Korea's national news agency Yonhap identified the man only by his surname, Won, and said he was in his mid-50s.
About a half-dozen South Korean diplomats tried to block the Chinese by forming a line outside a guardhouse where the man was held, said a Yonhap reporter who witnessed the incident.
But about a dozen Beijing municipal police who arrived by van forced their way into the guardhouse, kicking, punching and knocking down diplomats, said the reporter, Lee Sang Min. One diplomat was punched in the mouth in the scuffle, leaving bloodstains on the concrete at the office entrance.
A videotape shot by a journalist for South Korean broadcaster MBC showed police grabbing the man by his arms and legs, dragging him to the van and driving him away.
"The Chinese police took him away. We don't know to where," the South Korean official said.
The Chinese Foreign Ministry said it had no information about the incident. Government technicians cut transmission when one television agency began sending footage of the scuffle to its headquarters via the satellite service of state-run China Central Television.
South Korea's Foreign Ministry called the action a violation of international law and demanded China surrender the man to South Korean diplomats.
"We strongly protest and demand early return of the man," the statement said. "We hope this incident will be resolved smoothly on the basis of friendly relations between South Korea and China."
By treaty, diplomatic offices are considered foreign territory that Chinese authorities aren't supposed to enter without permission.
China is obliged by treaty with its hard-line communist North Korean ally to send home refugees, but has let asylum-seekers leave in cases that become public.
In May, Chinese guards seized five North Koreans from inside a Japanese consulate, prompting protests from Tokyo. China first claimed its guards had acted to protect the consulate, then said they were invited in. Japan denied its diplomats had asked the guards to remove the North Koreans.
The five were later allowed to leave for South Korea via the Philippines.
A spokesman for the U.N. High Commissioner for Refugees in Geneva expressed concern about the fate of the asylum-seekers.
"Some may be economic migrants and some refugees -- but the assumption given the situation in North Korea must be that some of them are fleeing persecution," Kris Janowski told The Associated Press.
He said that as a signatory of the 1951 Refugee Convention, China was obligated not to return refugees.
Janowski said the U.N. agency had a long-standing request to visit China's border with North Korea, because it wanted to assess the situation of people crossing into China. But Beijing had consistently refused access, he said.