The number of North Koreans who have resettled in the South fell 20.8 percent in the first half from a year ago as Pyongyang tightens border controls, the Unification Ministry said Wednesday.

A total of 593 North Koreans arrived in Seoul between January and June, down from 749 of the same period last year, ministry data shows, noting around 80 percent of them are women. This brings the cumulative sum of the defectors here to 30,805. 

Since he took power in December 2011, North Korean leader Kim Jong-un has been toughening border controls and punishment for unsuccessful escape attempts.

After reaching its peak at 2,914 in 2009, the yearly tally began to sharply dwindle under Kim, to 1,502 in 2012, 1,514 in 2013, 1,397 in 2014, 1,275 in 2015 and 1,418 in 2016. 

The regime appears to have since late 2015 installed high-tension wires in the border regions like the Tumen River basin, reinforced guard post surveillance and changed law to prevent failed runaways from being pardoned, according to an annual white paper on North Korea’s human rights issued last March by the ministry-affiliated Korea Institute for National Unification based on testimonies of 196 new arrivals.

“The number of defectors has indeed declined since Kim seized power including this year,” ministry spokesman Lee Duk-haeng said at a news briefing. “There may be various reasons behind the decrease but mostly internal factors should have played out, and we have yet to confirm the news reports on high-wire tension.”

By Shin Hyon-hee (heeshin@heraldcorp.com)