China appears to be tightening border security against North Korean defectors in the face of growing international pressure to end repatriations to the repressive state.

Multiple sources informed of Beijing’s border control efforts told local media that China recently installed a police alert system in each household of a border town on a trial basis.

Chinese residents there can push a button to inform security officers of any encounter with North Korean defectors, they said. Defectors who do not have any relatives in China usually seek help from the Chinese in the border areas.

“I visited my relative’s house and there was an alert system. If you push a red button on it, it then sends a signal directly to the police,” one of the sources said. “There is also a speaker-like piece of equipment attached to it, with which the conversation you have with defectors can be delivered to the police.”

China has refused to regard the defectors as refugees protected by international humanitarian conventions. It categorizes them as “economic migrants” illegally crossing the border.

In recent months, Seoul has revved up diplomatic efforts to persuade Beijing not to repatriate North Korean defectors. It had been criticized for “low-key, passive” diplomacy on the issue.

Seoul has also sought to appeal to the international community to address the issue. It recently raised defectors’ human rights at a U.H. human rights panel.

With Seoul making more overt efforts to address the humanitarian issue, some observers have cautioned against heaping too much pressure on China and the North.

Meanwhile, the U.N. Human Rights Council adopted a resolution on North Korean human rights without a vote at its 19th session in Geneva, Switzerland, on Thursday. It is the first time the panel endorsed it without a vote since it was first adopted in 2003.

The resolution, which was jointly submitted by Japan and the EU, calls for extending the term of the U.N. special rapporteur on human rights in North Korea by one year and urges the North to cooperate with the activities of the rapporteur.

Marzuki Darusman, former Indonesian prosecutorial chief, has served as the special rapporteur on Pyongyang since June 2010.

Among the UNHRC member states, China, Russia and Cuba expressed opposition to the resolution, but did not apply for a vote. Pyongyang rejected it, calling the resolution a byproduct of “political intrigue made up by hostile forces.”

In related news, U.S. lawmakers introduced a bill Thursday on continuing efforts to promote human rights in the North.

The bill calls for extending until 2017 the provisions of the North Korean Human Rights Act. The existing Act is intended to pressure Pyongyang over human rights, democracy and refugee protection among others.

More than 23,200 North Koreans have defected here since the 1950-53 Korean War.

The number of defectors steadily increased annually from 2005 until 2009: 1,383 in 2005, 2,018 in 2006, 2,544 in 2007, 2,809 in 2008 and 2,927 in 2009, according to the Unification Ministry.

It then dropped to 2,379 in 2010 when Pyongyang tightened its border control while preparing for its hereditary power succession. Last year, the figure rebounded to 2,737.

By Song Sang-ho (sshluck@heraldcorp.com)