Helping Hands Korea said border patrols on both sides of the Tumen and Yalu Rivers are being increased to stop illegal border crossers, The Korea Times reported.
For their part, Chinese police are making more house-to-house checks along border areas to crack down on refugees hiding out in ethnic Korean households living in China, the group said.
Helping Hands Korea also claimed it has received reports of "shoot-on-sight'' orders given to North Korean border guards who encounter people trying to cross the border illegally. Additionally, snipers have been posted at border stations along the Tumen River.
North Koreans have increasingly sought to escape amid poverty and worsening food shortages, the Times said.
South Korea's national intelligence agency has said that while North Korea faces a grain shortage, it is unlikely to lead to a famine. Upcoming international aid and the U.S. promise of 500,000 tons of provisions could fill much of the gap, the agency said.