Two North Korean women drowned last Friday on the arduous trek across Asia to South Korea when their boat capsized in the Mekong River on the border of Laos and Thailand. One of them had been traveling in search of cancer treatment.

A spokesman for an activist group said 12 North Korean women were crossing the Mekong River from Laos to Thailand around 3 p.m. Friday when their boat capsized. Ten were rescued, but a woman in her 50s and another in her 20s died. The younger woman's body was found, but the older remains missing.

A source said the small boat had a capacity of only about five passengers but the traffickers allowed all 12 of them on to save money.

The women left the Chinese province of Shandong early this month and crossed the border from Yunnan into Laos. The China-Laos-Thailand trek is an established escape route for North Korean defectors, who can avoid the risk of being sent back to the North only once they reach Thailand.

The two women had traveled 3,000 km and were just meters away from safety on the tranquil river.

According to the sources, the older woman came from Chongjin in North Hamgyong Province and had been sold to a Chinese man after fleeing the North two years ago. She had decided to escape to South Korea in search of a cure for her breast cancer. She had already once been arrested by Chinese police and sent back to the North. The dead women had no family in South Korea.

The number of defectors peaked at about 2,900 in 2009 but has been on the decrease due to tightening border controls and worsening relations between Pyongyang and Beijing since Kim Jong-un took power in 2012. Nevertheless, more than 1,000 defectors are arriving in South Korea annually, 1,127 last year.

The total number of defectors here stood at 31,339 as of late December last year.