Los Angeles, Sep 2 (DPA) The two US journalists captured and held in North Korea for months before being released last month revealed the first details of their ordeal Wednesday.

Laura Ling and Euna Lee, reporters for Current TV, wrote on its website that they were captured March 17 after briefly crossing a frozen river that marked the border between China and North Korea and which was often used as a human trafficking route.

Ling, 36, and Lee, 32, were sentenced to 12 years of hard labour for grave offenses against the North Korean government, but came home to a heroes' welcome after former president Bill Clinton flew to Pyongyang and interceded with North Korean leader Kim Jong-Il on their behalf.

The two were researching a story about women who fled the poverty of North Korea, only to find themselves forces into the online sex industry or into arranged marriages in China.

The journalists said they were aware they were crossing the border, but were already back on the Chinese side of the line when they were chased down by North Korean guards and dragged back over the border to an army camp. Their guide and a producer managed to outrun the guards and were never captured, they said.

'When we set out, we had no intention of leaving China, but when our guide beckoned for us to follow him beyond the middle of the river, we did,' the two wrote in the piece, titled Hostages of the Hermit Kingdom.

'We were firmly back inside China when the soldiers apprehended us. They violently dragged us back across the ice to North Korea and marched us to a nearby army base, where we were detained. Over the next 140 days, we were moved to Pyongyang, isolated from one another, repeatedly interrogated and eventually put on trial and sentenced to 12 years of hard labour.